Home

User Manual - University of Freiburg

1. The system is generated in the configuration file see Section 8 4 If users are interested in changing the FLORID system itself e g for investigating evaluation strategies they are provided with very flexible and declarative methods to configure their system 8 THE STRUCTURE OF THE FLORID SYSTEM 20 8 1 The User Interface The user interface sys has two main functions Firstly it manages the system components and their interaction and secondly it communicates with the user It encapsulates the FLORID system providing a single and uniform way of access queries in F Logic syntax That means that all user input whether he wants to load a database evaluate a program examine the calculated object model or customize the system has strictly to follow F Logic syntax System commands can be distinguished from data queries facts or rules as they are queries to sys a virtual host object representing the user interface Of course regarding their semantics such queries differ considerably from logical queries 8 2 Interface Objects The components of the FLORID system in Figure 4 as well as some other objects e g inte gers strings or blocks cf Section 4 2 are available at the user interface Since FLORID is an object oriented system all operations on system components are carried out by invoking methods on them In F Logic syntax this gives rise to path expressions of the form ob ject method or object method attribute a
2. pp l X Y pplprep gt W np gt 1 2 Y x amos flp Flp Font L34 48 This is FLORID Version 2 0 lt September 1997 gt Type sys help for further information z I a it XEmacs flp Inferior Flp zun L4 All prototype buffer program buffer Figure 2 XEmacs 19 13 in flp mode If the edited file does not end with flp the system can be started manually by the command Meta x run flp when pressing Meta x the emacs cursor jumps into the minibuffer where the command is entered Then again a new buffer is created 4 PROGRAMMING WITH FLORID 9 4 Programming with Florid Programs are collections of facts and rules similar to Prolog programs In addition to logical facts and rules system commands can be used for user interaction with FLORID The evaluation of programs is based on two concepts e The ObjectManager OM represents a set of derived facts The object manager can be emptied by calling sys forgetIDB facts are added by sys tp or sys eval see below e The FLogiclInterpreter interp holds a current program The interp interface object serves as an encapsulation for all logical operations dealing with programs and queries To add new facts and rules to the current program a program file has to be consulted Typing sys showProgram displays the current program note that this is not neces sarily the compl
3. setq load path cons home db florid environment load path 2 FLORID IN THE UNIX SHELL 6 have to be added to the emacs file or flp el has to be put into a directory where emacs looks for files In flp el it has to be specified where to find the florid executable If the florid bin emacs flp directory is in the binary search path mode defvar flp program name florid Program name for invoking an inferior Flp with run flp is sufficient Otherwise change it to the actual path Additionally florid environment default his has to be copied to florid history history file for the private readline history After these installation steps emacs has to be started again to let the changes take effect 2 Florid in the UNIX Shell FLORID is started from the shell by simply typing florid at the unix prompt When FLORID is started in the unix shell command line options can be given see Section 7 e g florid v yields the version number To give an impression of the FLORID system and its usage we present a short example session in the unix shell More example sessions are included in appendix C Let the file first_example flp contain the following program eagle bird fly gt yes brood gt eggs bob eagle which defines that eagles are birds birds fly and lay eggs Additionally bob is an eagle We want to evaluate the program first_example flp and query the database which is defined by this program da
4. according to individual needs Class objects have In conventional systems this would be done by environment variables 3In conventional systems this would be an environment variable assignment 8 THE STRUCTURE OF THE FLORID SYSTEM 21 the single method new to generate instances By convention the names of such objects begin with the prefix class Using class objects opens up the possibility to configure FLORID in various ways for exam ple with different evaluation components e g the semi naive evaluation module FLORID can even hold several separate systems at the same time The standard configuration of FLORID is build by the file config flp which is automatically consulted after startup if DEFAULTCFG is set and the c option is not used See Section 8 4 for details of the system building process Normally the class objects are only used in configuration files Interface objects can be manipulated and queried by the user These commands are of the form sys lt which_object gt lt expr gt e g sys centralStatistic show which is interpreted as follows The method centralStatistic is sent to the object sys which will return the respective interface object This in turn gets the method call show causing the statistics handler to print the runtime statistics table AN interface objects except the class objects have the following basic methods in common display outputChannel Display the actual contents or state pri
5. block declaration is a multivalued method definition with host object sys Between the curly braces stands a sequence of goals i e queries without Note that in contrast to the F Logic semantics of multi valued methods the goals form a list here not a set i e the order is relevant Note that you can use logical queries besides system commands in blocks too as far as they contain only one goal Stratification The interplay between the OM and the current program allows a user stratification of programs a set of rules which is a part of a larger program can be executed by the two system queries some rules sys eval sys forgetProgram some more rules sys eval First the first set of rules is evaluated by sys eval computing an OM Then the method forget Program clears the current program the contents of the OM remain unchanged and the second set of rules is evaluated wrt this OM Thus an important example is the definition of a block strat which makes stratification of programs more readable This is done in config flp by default cf Sec 8 4 sys strat gt gt sys eval sys forgetProgram Thus calling sys strat dolt executes sys eval and sys forgetProgram sequentially to separate the strata of a program simply put the command between them Besides the method doIt a block has the method display It lists the contents of the block as a list
6. config file instead of typing them again and again at the FLORID shell config flp Configuration file sys centralErrorHandler setOutputFilter 2 short error messages sys the0M gt class0OM new sys the0MAccess gt classWebOMAccess new the0 M sys theCreator gt classCreator1 new the0MAccess sys theAlgebraicEval gt classAlgebraicEval new theOMAccess sys theTranslator gt classTranslator new sys theMatcher gt classMatcher new theTranslator theCreator theAlgebraicEval sys theEval gt classPrSemiNaive new theMatcher theOMAccess sys theSemAnalyser gt classSemanticAnalyser new 8 THE STRUCTURE OF THE FLORID SYSTEM 23 sys prn gt classPrettyPrinter new the0MAccess sys interp gt classFLogicInterpreter new theEval prn theSemAnalyser sys switch interp the0M giveSymTab sys theNormalizer gt classNormalizer new interp sys strat gt gt sys echo sys echo BEGIN EVALUATION sys eval sys forgetProgram sys echo END EVALUATION sys evaluate gt gt sys strat doIt sys break gt gt sys strat dolt sys echo sys echo START QUERY SUBSHELL sys shell sys echo END QUERY SUBSHELL sys theO0MAccess setAccess all Explanation sys centralErrorHandler setQutputFilter 2 Display all error messages in short form sys the0M gt class0OM new Generate an object manager an
7. main directory florid is located at home db vironment Then the environment variables have to be set to Variables e DEFAULTCFG home db florid environment config flp e DEFAULTHIS home db florid environment default his You can set the variables either directly from the shell or automatically in an operating system file e g for the bash shell add the commands export DEFAULTCFG home db florid environment config flp export DEFAULTHIS home db florid environment default his to bashrc If you want to check if your settings are working proceed with Section 2 now for a first example The XML functionality May00 is only available when the environment variables SP_ENCODING XML and SGML_CATALOG_FILES home db florid sgml xml soc are set 1 4 Settings for Florid in Emacs Additionally to the shell emacs provides a very user friendly interface to FLORID via the emacs flp mode The emacs flp mode is defined in the file flp e1 which is located in in emacs flp florid environment To make emacs load and use this mode the local emacs file has to mode be extended by the following lines 333 enter flp mode if a file with the suffix flp is loaded setq auto mode alist cons flp flp mode auto mode alist 333 autoload flp el if the functions flp mode or run flp are executed autoload flp mode flp t autoload run flp flp t To be sure that emacs actually finds flp el either the lines
8. FLORIJ User Manual Version 3 0 FLOXML Wolfgang May may informatik uni freiburg de Institut fiir Informatik Universitat Freiburg Germany October 2000 This manual is based on the former versions by J rgen Frohn Rainer Himmer der Paul Th Kandzia Christian Schlepphorst and Heinz Uphoff CONTENTS Contents Preface 1 Installation 1 1 Installation of the Source Distribution 2 2 2 2 0 1 2 Installation of the Binary Distribution 1 3 Environment Variables 2 nn nen 1 4 Settings for FLORID in Emacs Florid in the UNIX Shell Running Florid in Emacs Programming with Florid 4 1 Programs and Evaluation 2 222 on nn 4 2 Blocks and Stratification 2 CC nommen Output 5 1 Output Formatting 2 onen 5 2 Output Handling 2 2 Cm onen 5 3 OME Browsing fe etek tie Ser See el eee ad 4 kan Debugging 6 1 Debugging the Evaluation 0 4 6 2 Tracing the System Input 04 6 3 Tracing of Object Equating 20 Invoking Florid Command Line Options The Structure of the Florid System 8 1 The User Interface 2 Ene pTi e 0200002000 8 2 Interface Objects oaoa aaa ee ee 8 3 Restrictions for System Commands 8 4 System Configuration in config flp Florid System Commands B Readline and History Commands C Example Sessions G 1 Eyaluating a a el ee C 2 Help mech
9. LORID system We assume that the reader is familiar with the basic notions of F Logic For details about the language and data modeling with F Logic the reader is referred to the FLORID programming tutorial FHM 00 and the F Logic report KLW93 The structure of this manual is as follows The first part describes the installation and the environment of FLORID First we give describe the installation of Florid for working from the unix shell or from within emacs Section 2 gives a short example of how to run FLORID and in the unix shell Working with FLORID in emacs is described in Section 3 The second part serves as user manual to FLORID for everyday s use as F Logic engine Section 4 is a manual to programming with FLORID from the user s point of view describing the evaluation of programs and the main system commands for user interaction and controlling evaluation Section 5 describes how the output of FLORID can be handled Section 6 illustrates how programs can be debugged The third part addresses the more involved users which want to experiment with FLORID including changing its behavior nevertheless it should also be of interest for simple users Section 7 describes command line options for invoking FLORID as an experimental system Section 8 describes the system itself its object oriented design and the deeper background of system commands Also it is explained how the user can change the configuration of an experimental sy
10. al use sys eval for complete evaluation which means iteration of deductive fixpoints and inheritance Note that the object manager is not cleared before applying Tp that is the evaluation does not start with the empty set by default This is an important feature for dividing large programs into smaller parts or for user stratification using sys strat doIt see Section 4 2 Sometimes the user may want to cancel a running evaluation without terminating the whole system This can be done by pressing Control This key sends a QUIT signal to the system which causes a break flag to be set In order to return a somewhat consistent object world the current Tp round has to be finished so that it possibly takes some time before the system actually halts After canceling the partial model evaluated up to this point can be examined by querying Calling sys eval again will continue the evaluation process where it was halted The pretty printer checks the QUIT signal too so that printing huge answer sets can be stopped Semi naive Evaluation FLORID includes an evaluation component providing a semi naive evaluation mode The evaluation mode can be set by a system command sys theEval mode seminaive sys theEval mode naive Naive evaluation is the default setting Evaluating in semi naive mode is promising for recur sive programs with many TP rounds to make up for the overhead due to program analysis rewr
11. anism 2 2 En nn C 3 System commands in files 2 2 2 En nn References o outer Ko 12 12 15 15 15 16 17 17 18 19 20 20 21 22 25 26 27 27 30 34 35 CONTENTS 3 Preface With FLORID F LOgic Reasoning In Databases an implementation of a programming system based on the concepts of F Logic is presented Proposed by Kifer Lausen and Wu KLW95 F Logic is designed as a logical language accounting in a clean declarative fashion for most of the structural aspects of object oriented data modeling Contrasting other approaches e g Law93 GULOG DT95 and ROL Liu96 nearly all of the distinctive F Logic features are realized in FLORID In particular we emphasize that the system supports data driven schema definition multiple non monotonic inheritance and furthermore path expressions FLU94 which can also be used for anonymous object creation The evaluation of programs is based on a set oriented bottom up computation as an extension of the algorithm well known from Datalog AHV95 CGT90 Ull89 also a semi naive evaluation component is provided With version 2 0 FLORID has been extended with Web access see tutorial FHM 00 for details The FLORID system was developed at the universities of Mannheim and Freiburg as part of a research project granted by the DFG Deutsche Forschungsgemeinschaft under leadership of Georg Lausen The aim of this manual is to demonstrate the usage of the F
12. ar mode String Here the lexical representation of internal names can be customized This matters if more than one such representation exists for example when using path expres sions or equating objects The parameter may be poor Display internal names const Constants will be printed with their lexical representation and other objects path expression and complex IdTerms as internal names first Shows the first lexical representation found best For each object the best that is shortest existing lexical representation is printed Of course all possible representations have to be found and compared so this is the slowest output mode Example peter father gt mary husband sys eval sys prn mode poor X father gt Y Answer to query X father gt Y X o5 Y o9 sys prn mode const X father gt Y Answer to query X father gt Y X peter Y o9 sys prn mode first 5 OUTPUT Figure 3 Answer display in html style X father gt Y Answer to query X father gt Y X peter Y peter father sys prn mode best X father gt Y Answer to query X father gt Y X peter Y mary husband sys prn style instance X father gt Y 14 6 DEBUGGING 15 Answer to query X father gt Y peter father gt mary husband 5 2 Output Handling All output from FLORID is communicated via output channe
13. ct Manager debugOn enter debug mode for consult debugOff eqTraceOn enter debug mode for tracing equatings eqTrace ff the0OM showFrame arg display object frame theOM showFrame pred n display predicate frame of pred for arity n B READLINE AND HISTORY COMMANDS 26 Additional help is also available sys help lists all methods of sys sys display lists all interface objects Each of the above interface objects adressible by sys lt interface obj gt provides the method sys lt interface obj gt help which lists its methods B Readline and History Commands The following tables list the key commands available for the readline and the history packages they were taken from FR94 The shortcut C k is read Control k and describes the character produced when the Control key is pressed and the k key is struck The text M k is read as Meta k and describes the character produced when the meta key if you have one is pressed and the k key is struck If you do not have a meta key the identical keystroke can be generated by typing ESC first and then typing k Either process is known as metafying the k key C _ Undo the last thing that you did C a Move to the start of the line C e Move to the end of the line M f Move forward a word M b Move backward a word C 1 Clear the screen reprinting the current line at the top C k Kill the text from the current cursor position to the end of the line C u Ki
14. d assign it to the interface variable theOM sys theOM Access jclassWebOM Access new theOM An Object Manager Accessor OMA encapsulates read access to the object manager There fore it needs the OM as a parameter sys theCreator gt classCreatori1 new the0MAccess sys theAlgebraicEval gt classAlgebraicEval new the0MAccess sys theTranslator gt classTranslator new These three objects are needed by the matcher as part of the evaluation process sys theMatcher gt classMatcher new theTranslator theCreator theAlgebraicEval Now the matching component is generated which may get an optimizer too as an additional parameter No such component has been implemented up to now though sys theEval gt classPrSemiNaive new theMatcher theOMAccess This configuration file uses a semi naive evaluation component sys theSemAnalyser gt classSemanticAnalyser new A component used by the FLSysInterpreter the front end user interface to check queries for safety sys prn gt classPrettyPrinter new the0OMAccess The pretty printer displays answer sets in readable form To do this it needs access to the object manager syslinterp gt classFLogicInterpreter new theEval prn theSemAnalyser 8 THE STRUCTURE OF THE FLORID SYSTEM 24 The FLogicInterpreter serves as an interface between the user front end FLSysInterpreter and the pure F Logic part of the system Here all input except system comma
15. de defines several key codes for interaction between the editor and FLORID see Table 1 3 RUNNING FLORID IN EMACS 8 Reset System and consult buffer as file Consult additional same as C c C c but without system reset Consult marked region without reset System reset clear OM and program Consult whole buffer as region without reset Display buffer flp and jump there Break evaluation or output Quit FLORID process Table 1 Special keycodes in the flp mode When the key combination Control c Control c is pressed in the program buffer a new buffer is created in the lower half of the current buffer In this buffer FLORID is started and consults and evaluates the program given in the program buffer see Figure 2 Then the user can interact in the same way with FLORID as described before for the unix shell Additionally it is possible to step through the history by Meta P Previous and Meta N Next The difference between C c C a and C c C b is that in the second case the buffer s contents is not saved before calling FLORID emacs flp al File Edit Apps Options Buffers Tools Comint Comint2 History 1l X Y zs np gt 1 X 2 vp gt 1 2 Y 1 X Z snp 1 2 Y vp 1 Y zs s gt 1 X 2 pp gt 1 2 Y 1l X Z s 1 2 Y pp nounsenp l X Y znp ldet gt W1 noun gt W2 1 X Z det w gt W1 1 2 Y noun w gt W2 1 Y znp np gt l X 2Z pp gt 1l 2 Y IL X Z2 enp 1 2 Y
16. e program is reached control is given back to the calling level interactive mode or another consult The OM then contains a model of the program evaluated so far Program evaluation As already mentioned FLORID uses a bottom up evaluation strat egy This algorithm iteratively deduces new facts from already established facts using a forward chaining technique CGT90 A program P gives rise to an operator Tp on partial 4 PROGRAMMING WITH FLORID 10 models for F Logic defined in KLW95 This operator adds all those facts to the model which can be derived from the already existing facts by a single application of a program rule no recursion To evaluate recursive rules it is necessary to iterate this operator Starting with the empty model or a given finite object world a fixpoint TR is reached after a finite number of applications of Tp After that FLORID tries to deduce a new fact by inheritance If such a fact is found Tp is applied again until another fixpoint is reached This process continues until no new information can be inherited The resulting partial model is a model for the program P When there are several possible facts inheritable at the same time FLORID chooses one of them nondeterministically Thus the model of P is not unique For a formal treatment of the semantics of F Logic and implemented algorithm see KLW95 A single application of Tp can be achieved with sys tp although the user will in gener
17. e system from the emacs not only offers high level editing facilities but also inte grates FLORID into an environment where all kinds of tools mailreader newsreader several compilers TeX etc are used in a uniform way In order to use FLORID from emacs the configuration steps in Section 1 4 must have been executed When a file ending with flp is loaded into emacs emacs automatically enters the F Logic mode Figure 1 For editing the flp mode provides syntax highlighting facility to make F Logic programs using the font lock package shipped with XEmacs 19 13 or higher it is recommended to set Syntax Highlight ing Colors and Auto Fontify in the XEmacs Options menu If font lock is not available syntax highlighting does not work pp emacssamos fp E SS Sy Ses Ol Size s 2 e det determiner CHE 1 X Y s np gt 1l X 2 vp gt 1 2 Y 1 X 2 snp 1 2 Y vp 1 X Y s e gt 1L X 2 pp gt 1 2 J l X 2 s 1 2 Y pp noun inp l X Y znp det gt W1 noun gt W2 1 X 2 det w gt W1 1 2 Y noun w gt W2 1 X Y snp np gt 1 X 2 pp gt 1 2 Y l X Z2 snp 1 2 Y pp 1 X Y pplprep gt W np gt 1 2 Y l X 2 prep w gt W 1 2 Y np 1 X Y vplverb gt W np gt 1 2 Y 1 X 2 verb w gt W 1 2 Y inp f dictionary johninoun amos flp Flp 46 minibuffer program buffer Figure 1 XEmacs 19 13 Additionally to editing capabilities the flp mo
18. ense only in the case of very small models Otherwise the frames to be watched can be specified see below insert If this parameter is given all inserts to the object model are reported The re spective rule is displayed together with the set of variable bindings delta This is a special mode for semi naive evaluation After each Tp round the contents of all delta predicates needed for the actual program are printed trigger In this mode all facts derived by firing inheritance triggers are reported when they are inserted into the object model frame Any other string is interpreted as the name of an object frame to monitor The frame is printed after each Tp round frame n If an integer follows after a string the string is considered as the name of a predicate frame with arity n The frame is printed after each Tp round These parameters may be combined deliberately e g sys theEval debug0n program delta sales expenditures Debugging is turned off by the command sys theEval debugOff Additionally it is possible to apply the Tp operator by hand with the command sys tp and to examine the OM state afterwards by querying or browsing Subsequent calls of the methods tp and eval will continue the evaluation with the current state of the OM The contents of the OM i e all object and predicate frames can be displayed through sys theOM dump This command is useful if only a small nu
19. eported sys theOM eqTraceDff leaves this mode again Example peter father gt mary husband peter father gt john Evaluation with egTraceOn yields Equality mary husband 07 made equal to john 08 The OIDs of the equated objects are shown in parentheses Equating two objects may cause other equatings e g in the case of scalar methods With path expressions such equatings may seem superfluous because the objects already have identical names Listing the OIDs reveals that those equatings are indeed necessary michael father mike father michael mike Evaluation with eqTraceOn yields Equality michael 05 made equal to mike 08 Equality mike father 07 made equal to mike father 09 7 INVOKING FLORID COMMAND LINE OPTIONS 18 7 Invoking Florid Command Line Options When FLORID is started in the unix shell by entering florid command line options can be given A list of possible options is printed with florid h If h or an undefined option is given FLORID terminates after printing an appropriate message naxos florid bin gt florid h This is Florid Type sys help for further information Florid Options h display all options c lt fileName gt use non default configuration file his lt fileName gt use non default history file d start in trace mode e lt Integer gt set output level for errors lt list lt fileName gt gt start and consult files separated by b
20. ete program file see Section 4 2 and sys forgetProgram discards it Note that the current program is independent of the contents of the object manager the link between these two is the evaluation of the current program wrt the OM which changes the OM 4 1 Programs and Evaluation Consulting a program After entering sys consult foo flp or typing C c C c in an emacs program buffer holding the program the following happens The user interface reads foo flp rulewise using the F Logic parser e Facts und rules are added to the current program held by the FLogicInterpreter interp Note that no evaluation takes place until the system query sys eval is encountered e Queries are answered immediately System queries are executed by sending messages to interface objects Syntactically system commands are scalar path expressions of the form sys expression Most system commands which are relevant to the user are directly applied to the user interface object called sys e g for sys eval the current program is evaluated wrt the current state of the OM Additionally interface objects see Section 8 2 can be manipulated and queried by the user via system commands Other queries are passed to interp which answers them according to the current state of the OM e In case of a syntax error the consult process is terminated and the error is reported at the text shell When the end of th
21. he program edge flp and query the computed model naxos florid bin gt florid This is FLORID Type sys help for further information sys consult edge flp load edge flp sys eval start evaluation of current program p el P path logical query to the model computed Answer to query p e1 P path answer set is printed P e2 P p e2 e5 P p e2 p e5 e6 3 output s printed sys end quit FLORID Bye naxos florid bin gt Scenario 2 Evaluate edge flp discard the computed model and evaluate again by single step Tp application to see how the answer set changes Instead of typing sys consult edge flp the filename is given in the command line C EXAMPLE SESSIONS naxos florid bin gt florid edge flp This is FLORID Type sys help for further information sys eval start evaluation sys forgetIDB clear the OM program remains unchanged sys tp apply TP operator once TP Round 0 p e1 P path query the partial model yet computed Answer to query p e1 P path false answer set is enpty sys tp apply TP again TP Round 1 p el P path Answer to query p e1 P path P e2 1 output s printed sys tp TP Round 2 p el P path Answer to query p e1 P path P e2 P p e2 e5 2 output s printed sys tp TP Round 3 p el P path Answer to query p e1 P path P e2 P p e2 e5 P p e2 p e5 e6 3 output s pri
22. ichard Hull and Victor Vianu Foundations of Databases Addison Wesley 1995 CGT90 S Ceri G Gottlob and L Tanca Logic Programming and Databases Springer 1990 DT95 Gillian Dobbie and Rodney Topor On the declarative and procedural semantics of deductive object oriented systems Journal of Intelligent Information Systems 4 2 193 219 1995 FHM 00 J Frohn R Himmer der W May P Th Kandzia and C Schlepphorst How to write F Logic programs in FLORID 2000 Available from http www informatik uni freiburg de dbis florid FLU94 J rgen Frohn Georg Lausen and Heinz Uphoff Access to objects by path ex pressions and rules In Intl Conference on Very Large Data Bases VLDB pages 273 284 1994 FR94 Brian Fox and Chet Ramey GNU readline library edition 2 0 for readline library version 2 0 Free Software Foundation Cambridge MA 1994 KLW95 Michael Kifer Georg Lausen and James Wu Logical foundations of object oriented and frame based languages Journal of the ACM 42 4 741 843 1995 Law93 Michael Lawley A Prolog Interpreter for F Logic Technical report Griffith University Australia 1993 Liu96 M Liu ROL A typed deductive object base language In Intl Conference on Database and Expert Systems Applications DEXA 1996 May00 W May Handling XML with FLORID 2000 Available from http www informatik uni freiburg de dbis florid Pfe95 Thorsten Pferdek mper Eine flexible Konfiguratio
23. ics naxos florid bin gt florid edge flp This is FLORID Type sys help for further information sys eval p el P path query the model Answer to query p e1 P path P e2 P p e2 e5 P p e2 p e5 e6 3 output s printed sys centralStatistic show show runtime statistics C EXAMPLE SESSIONS 30 Time spent in semantic analyses 0 03sec real 0 02sec user Time spent in retrieving 0 16sec real 0 15sec user Number of TP iterations 5 Total time spent in evaluation 0 34sec real 0 24sec user Time spent in computing answers 0 0isec real 0 01sec user Time spent in pretty printing 0 22sec real 0 00sec user p el P path Answer to query p e1 P path P e2 P p e2 e5 P p e2 p e5 e6 3 output s printed sys centralStatistic show show statistics again Time spent in semantic analyses 0 03sec real 0 02sec user Time spent in retrieving 0 16sec real 0 15sec user Number of TP iterations 5 Total time spent in evaluation 0 34sec real 0 24sec user Time spent in computing answers 0 02sec real 0 01sec user Time spent in pretty printing 0 00sec real 0 00sec user sys centralStatistic clear reset statistics sys centralStatistic show and display again statistic is empty This scenario shows that the runtime statistics entries accumulate until the user discards them explicitely The first column real lists the absolute time difference between start and end while the seco
24. iting and delta predicate maintainance Semi naive evaluation will probably be slow for programs that derive new hierarchy facts or equate objects often because this makes dependancy analysis very hard See Sch97 for details about semi naive evaluation for F Logic To see the rewritten program set the debug mode program see Section 6 1 Due to the existence of function symbols and object creating path expressions some programs need countably many iterations to reach a fixpoint Such programs will not terminate in FLORID See the tutorial for examples 4 PROGRAMMING WITH FLORID 11 Everyday s System Commands sys consult foo flp read the program file foo see Sec 4 1 y P prog p sys load foo flp load a program file containing only facts directly into the OM sys eval evaluate the current program i e calculate a model sys strat dolt evaluate a stratum see Sec 4 2 sys echo print argument string sys break dolt stop program execution and get into interactive mode sys return continue program entered in interactive mode after sys break dolt sys end exit FLORID System commands are also used for output formatting and redirection see Sec 5 Appendix A lists all system commands and Appendix C contains a number of exam ple sessions that demonstrate the use of system commands more explicitly A number of frequently used system commands are loaded to the readline history C
25. lank q quit after executing no interactive mode v prints version number The option c denotes a configuration file to be used instead of the standard configuration file specified in the environment variable DEFAULTCFG cf Section 8 4 Similarly the option his loads the given file into the readline history instead of the default in DEFAULTHIS For operating FLORID with non standard configuration files regularly it is more convenient to change the environment variables cf Appendix 1 3 In addition to the options a list of filenames of F Logic programs can be given FLORID consults them in a left to right order see Section 4 1 for details about consulting In the example from Section 2 one could reduce typing by invoking florid first_example flp Then the consult command is automatically executed With option d debug all rules read will be echoed to the console This is useful for tracing configuration errors and locating errors in program files Option e errormode followed by a number customizes the system error messages Pos sible values are listed in Table 2 The option q causes FLORID to quit after execution of the command line instead of entering the interactive mode If option q is not given FLORID enters the interactive mode after having processed the command line Number No kind of system message is displayed Only messages but no warnings and errors are displayed Errors are displayed Any kind of system mes
26. ll backward from the cursor to the beginning of the current line M d Kill from the cursor to the end of the current word or if between words to the end of the next word M DEL Kill from the cursor the start of the previous word or if between words to the start of the previous word C y Yank the most recently killed text back into the buffer at the cursor TAB Attempt to do completion on the text before the cursor M List the possible completions of the text before the cursor Table 3 Important readline commands C p Move up through the history list You can also use the f key C n Move down through the history list You can also use the key M lt Move to the first line in the history M gt Move to the end of the input history i e the line you are entering Table 4 Important history commands C EXAMPLE SESSIONS 27 C Example Sessions In this section we present and comment some FLORID sessions in order to demonstrate the use of system commands User input and system output is printed in the typewriter style comments in italics C 1 Evaluating Let the file edge flp consist of the following F Logic program el edge 1 gt n1 2 gt n2 e2 edge 1 gt n2 2 gt n4 e3 edge 1 gt n1 2 gt n3 e4 edge 1 gt n3 2 gt n4 e5 edge 1 gt n4 2 gt n5 e6 edge 1 gt n5 2 gt n6 edge path p E P path 1 gt X 2 gt Z E edge 1 gt X 2 gt Y P path 1 gt Y 2 gt Z Scenario 1 Evaluate t
27. ls Output channels wrap stan dard C output streams and can be redirected centrally There are six predefined channels answerChannel for query results Main output of pretty printer errorChannel for error messages and warnings statisticChannel for runtime statistics generated by the statisticHandler helpChannel for output of help methods debugChannel for debug information if some debug mode is enabled systemChannel for all other output generated by the system Default output for all display and print methods To redirect the output sent to a channel the output stream wrapped by an output channel can be changed with setStream e g sys errorChannel setStream cout Initially answerChannel helpChannel and statisticChannel write to cout the other channels to cerr The command resetStream will restore this setting for a channel E g all output can be sent to the file myfile flp in the current directory sys output gt sys open myfile flp sys answerChannel setStream output produce some output sys answerChannel resetStream sys remove output By removing the interface object output the file is automatically closed This also happens when leaving FLORID To suppress printing it is also possible to direct unwanted output to the stream devnul available at the user interface e g sys systemChannel setStream devnul 5 3 OM Browsing The complete OM can be o
28. mber of frames are stored in the OM For larger models it is preferable to directly inspect the frames of interest An object frame can be printed with the command sys theOM showFrame arg where arg is the lexical representation of the object If showFrame has two parameters the string is considered as the name of a predicate frame with arity given as second parameter sys the0M showFrame ancestor 2 6 DEBUGGING 17 prints the contents of the predicate frame corresponding to the binary predicate ancestor Any Web action see tutorial FHM 00 can be monitored with sys theOMAccess debugOn 6 2 Tracing the System Input If the parser reports errors or problems with consulting files and system commands occur it may be helpful to see what the parser actually reads After setting the debug mode of the user interface sys by the command sys debugOn every line of input to the parser is echoed to the debug channel Note that you can also enter this mode by starting florid with the d option The command sys debugOff turns the system debug mode off 6 3 Tracing of Object Equating During evaluation of a program the application of the scalarity constraint a cyclic class hierarchy or explicit use of equality in a rule head can force objects to be equated If this is unintended it may lead to an unexpected behavior of the program In the equating trace mode set by sys theOM eqTraceOn any equating of objects is r
29. method args System queries have to consist of a single goal sys eval sys forgetProgram System query with more than one literal in body Split the query into simple ones If a goal starting with sys is not the leftmost goal of a query it is not recognized as a system command and treated as a query to the model instead johnlage gt X sys end Answer to query johnlage gt X sys end false 8 4 System Configuration in config flp The system is generated in the configuration file If users are interested in changing the FLORID system itself e g for investigating evaluation strategies they are provided with very flexible and declarative methods to configure their system Writing or modifying configuration files requires a detailed knowledge of internals of the system and should be used with care If FLORID is called without the c option it first consults the file pointed to by the environment variable DEFAULTCFG normally this is the file config flp This generates the components of a standard FLORID system and links them The process is echoed if the option d was given In addition to building the system the config file can also be used to configure some interface objects differently than by default To have semi naive evaluation instead of the default naive evaluation append sys theEval mode seminaive to the config file It is useful to add all permanent customizations to the
30. nd column user yields the CPU time consumed by the task The difference may vary due to other tasks running in parallel e g kernel window manager Additional to the measured time the number of Tp iterations is displayed If new facts were derived through inheritance the number of these facts fired inheritance trigger is printed too C 2 Help mechanism Starting point of all system commands is the host object sys the so called FLSysInterpreter Therefore all system commands begin with sys Besides the built in methods of the interpreter which can be listed by sys help its attributes the interface objects are handled as methods too Sometimes it may not be clear for the user which interface object understands which methods Therefore all interface objects representing instances of C classes provide the method help Those objects representing the classes itself do not have this method The next two scenarios shall explain how to navigate through the user interface Per convention the names of these objects start with the prefix class C EXAMPLE SESSIONS Scenario 1 in the standard configuration file This is FLORID Type sys help for further information sys display show attributes of interpreter FLSysInterpreter answerChannel anQutputChannel centralErrorHandler anErrorHandler centralStatistic aStatisticHandler classBlock Block classCreatori Creatori classFLogicInter
31. nds is pro cessed The FlogicInterpreter manages the evaluating component the pretty printer and the SemanticAnalyser sys switch interp the0M giveSymTab For passing actions the FLSysInterpreter needs to know interp and the system s symbol table They cannot be given as parameters because they are generated later than the FLSys Interpreter sys strat gt gt syslevaluate gt gt sys break gt gt With this command blocks for user stratification and program interruption are defined Acknowledgements First of all we want to thank Georg Lausen the head of our group who made the FLORID project possible Furthermore our thanks go to the former team members J rgen Frohn Rainer Himmer der Paul Th Kandzia Bertram Lud scher Chris tian Schlepphorst Markus Seilnacht and Heinz Uphoff who developed FLORID up to version 2 0 together with students from the universities at Mannheim and Freiburg A FLORID SYSTEM COMMANDS 25 A Florid System Commands Most system commands which are relevant to the user are directly applied to the user interface object called sys The following system commands are of interest for everydays users sys consult foo flp read the program file foo fip sys sys sys sys sys sys sys sys load foo flp load a program file containing only facts directly into the OM tp apply Tp operator of current program once to the current OM e
32. ns und Benutzerumgebung f r F Logik Diplomarbeit Universit t Mannheim 1995 Sch97 Christian Schlepphorst Semi Naive Evaluation of F Logic Programs Technical Report 85 Universit t Freiburg 1997 Str92 Bjarne Stroustrup The C Programming Language Addison Wesley 2nd edi tion 1992 U1189 Jeffrey D Ullman Principles of Database and Knowledge Base Systems volume 2 Computer Science Press New York 1989
33. nt outputChannel Print class or type of the object help List all methods understood by the object The parameter specifying the output channel may be omitted systemChannel is used by default 8 3 Restrictions for System Commands For system commands only a subset of the full F Logic syntax FHM 00 is allowed The restrictions are listed below On violation the respective error message is reported 1 No function symbols are allowed i e complex terms like functor varname Use methods with parameters instead methname param sys consult test flp Function symbols with arguments are not allowed in system commands Maybe a is missing 2 The called method must be defined for the host object sys theEval foo Unknown method foo Sending the help method to any interface object lists the methods that are defined for this object 3 Additionally sys treats the interface objects as methods yielding themselves so these must exist before calling Otherwise sys reports an unknown method call sys anotherEval help Unknown method anotherEval 4 No variables i e names beginning with upper case letters are allowed sys Eval Variables are not allowed in system commands THE STRUCTURE OF THE FLORID SYSTEM 22 Use identifiers starting with lower case characters Set valued path expressions are forbidden sys eval Only simple scalar paths are allowed in system commands Use format sys object
34. nted sys tp FP reached in round 4 further application of TP yields no new facts Model evaluated a fixpoint is reached no inheritance was possible 28 C EXAMPLE SESSIONS 29 Scenario 3 Evaluate edge flp then consult anc flp After checking the current program and evaluating it discard program and object model to evaluate another program test f1p from scratch naxos florid bin gt florid edge flp This is FLORID Type sys help for further information sys eval start evaluation of current program sys consult anc flp load anc flp sys showProgram display the current program el edgeli gt ni 2 gt n2 e2 edge 1 gt n2 2 gt n4 e3 edge 1 gt ni 2 gt n3 e4 edge 1 gt n3 2 gt n4 e5 edge 1 gt n4 2 gt n5 e6 edge 1 gt n5 2 gt n6 edge path p E P path 1 gt X 2 gt Z E edge 1 gt X 2 gt Y P path 1 gt Y 2 gt Z X anc gt gt Y X father gt gt Y X anc gt gt Y X anc father gt gt Y sys forgetProgram discard the current program sys showProgram This FProgram is empty sys forgetIDB clear OM discard model sys consult test flp read test flp sys eval and evaluate it As it is seen from this session sys consult does not discard the current program it adds new rules Scenario 4 After evaluating edge flp display the runtime statist
35. of queries adding the query prompt In the example above calling the method sys strat display will print Block sys eval sys forgetProgram 5 Output 5 1 Output Formatting There are several possibilities of printing answer sets depending on the desired representa tion style and whether maximum speed or readability is preferred The display modes are customized by the following methods of the pretty printer represented by the interface object prn providing the methods 5 OUTPUT 13 sys prn style lt argument gt and sys prn mode lt argument gt style String The parameter determines whether answers should be printed as fully in stantiated molecules or in prolog style as variable bindings to objects instance Display answers as fully instantiated molecules E g for our introductory example X fly gt yes Answer to query X fly gt yes bob fly gt yes bound Display answers in prolog like style with variables and objects bound to them X fly gt yes Answer to query X fly gt yes X bob html Same as bound but writes answers to an html file and sends this file to a netscape browser The html style is in particularly useful when dealing with Web queries see also FHM 00 In the html file the resulting urls are tagged as links so you can access them directly from the browser To clear the html file type sys prn cle
36. omments FLORID program files may contain comments There are three different com ment formats available in FLORID As in C and C text between and is ignored In this case the text may extend over more than one line When a C Style or a logic programming ATEX is found the rest of the line is considered as a comment These formats may be mixed deliberately Nested Programs File consulting can be nested without restriction The interface vari ables may serve as a kind of parameters here Consider a file execute flp containing the following lines sys consult filename sys eval sys echo filename sys echo The answer set is result X Querying the model sys forgetProgram In another file you can define filename and call execute sys filename gt myfile flp sys consult execute flp sys filename gt yourfile flp sys consult execute flp 4 2 Blocks and Stratification Sequences of queries in practice this concerns mainly system commands can be combined in a block A block is an interface object providing the method doIt This executes the queries contained in the block Of course the same effect could be achieved by consulting a file with 5 OUTPUT 12 the commands or queries But for short command series often recurring it is more convenient to use a block as a shorthand without having to consult external files Syntactically a
37. preter FLogicInterpreter classGraphicInterface GraphicInterface classMatcher Matcher classPrSemiNaive PrSemiNaive classPrettyPrinter PrettyPrinter we don t list all interface objects here classSemanticAnalyser SemanticAnalyser classStatisticHandler StatisticHandler cout aFLSysOStream debugChannel anQutputChannel devnul aFLSys0Stream errorChannel anQutputChannel helpChannel anQutputChannel interf aGraphicInterface interp aFLogicInterpreter prn aPrettyPrinter statisticChannel anQutputChannel strat aBlock theAlgebraicEval anAlgebraicEval theCreator aCreatori theEval aPrSemiNaive theMatcher aMatcher theNormalizer aFLSysObject theOI an0I theOM aFLSysObject theSemAnalyser aSemanticAnalyser theTranslator aTranslator sys help show built in methods of interpreter Online help for class FLSysInterpreter Which attributes and methods has the interpreter after building the system C EXAMPLE SESSIONS 32 You can apply the following member functions to an instance of class FLSysInterpreter via F Logic shell help isOk returns 0 object is corrupted or 1 isA String String classname returns 1 object belongs to class or 0 print prints type of instance display displays components end leave the flogic system eval evaluate the current program tp apply TP operator once showProgram show the current program forgetProgram clear the current
38. program forgetIDB clear the object manager switch link a new FLogicInterpreter to sys debugOn echo lines read while consulting debug ff interpreteLine String String command in flogic syntax interpreteFile String String filename open String opens a FLSys0Stream pointing to a file String filename Usage sys mystream gt sys open logfile echo String String displayed on output stream remove String String name of interface object to remove In the output generated by sys display both the C classes and instances appear The line classOI OI means that classOI represents the C class OI at the user interface C EXAMPLE SESSIONS 33 Furthermore the0I anOI describes that theOI is an instance of the class OI To all interface object displayed on the left side of e g theOI prn theEval etc you can apply help to see which methods are defined for them Scenario 2 Which methods can be sent to the interface object prn This is FLORID Type sys help for further information sys prn help apply the method help to prn Online help for class PrettyPrinter You can apply the following member functions to an instance of class PrettyPrinter via F Logic shell help isOk returns 0 object is corrupted or 1 isA String String classname returns 1 object belongs to class or 0 print OutputChannel OutputChannel e g answerChannel display Out
39. putChannel OutputChannel e g answerChannel style String String describes output style possible arguments are 1 bound answers are printed in Prolog style 2 instance answers are printed in F Logic syntax 3 html answers in Prolog style are written to an html file that is displayed by netscape mode String String describes representation of objects possible arguments are 1 poor only OID s are printed 2 const only strings of constants are printed 3 first first string for object is printed 4 best best string for object is printed clear remove stored information and clear html file of html style sys prn style instance set fact style for output sys prn isOk send method isOk to prn The return value of isOK is not printed by the user interface you have to apply the method display cout onto the return value This applies to all methods returning strings or integers sys prn isOk display cout send isOk to prn C EXAMPLE SESSIONS 34 and print the return value on cout C 3 System commands in files Placing system commands into files is useful in the following situations e system configuration Sec 8 4 e automation of processes to avoid unnecessary typing e generation of output for test purposes e user stratification by hand Sec 4 2 Scenario 1 Evaluate the file edge flp and examine the model without having to type sys eval and the query it at
40. ral definitions needed when using SGML docu ments The directory florid doc contains postscript files of the user manual manual ps and the FLORID tutorial tutorial ps Additional publications related to F Logic and FLORID are available from http www informatik uni freiburg de dbis Publications In florid examples a number of F Logic example programs are found For the examples from the tutorial there is an extra subdirectory florid examples tutorial Please send enquiries comments suggestions and bug reports to florid informatik uni freiburg de 1 INSTALLATION 5 1 3 Environment Variables Shell environment variables are used to set paths leading to FLORID s configuration files which are needed when Florid is called It is also possible to specify the paths by command line options when calling FLORID see Sec 7 The following variables should be set before starting FLORID e DEFAULTCFG e DEFAULTHIS DEFAULTCFG tells how to find the configuration file and DEFAULTHIS points to the history file to preload The configuration file is a sequence of system commands that create the objects needed for a working system and then pass control to the user See Section 8 4 for details If one of these variables is not set and the respective command line option is missing the system will print a warning In case of a missing DEFAULTCFG the FLORID system has to be built by hand UNIX En In the following we assume that FLORID s
41. sage is displayed D Table 2 Parameters for Option e 8 THE STRUCTURE OF THE FLORID SYSTEM 19 8 The Structure of the Florid System The FLORID system is implemented in C Str92 Due to the object oriented programming style in C it seemed reasonable to transfer this modeling style to the user interface too Pfe95 This resulted in a flexibly configurable system Important internal classes and objects of the system are directly accessible from the user interface and are combined from there Thus the structure of the FLORID system is reflected by the user interface Fig 4 At the bottom is the so called Object Manager which handles the data storage The User Interface on top is the front end and communicates with the user processes queries and sends the appropriate messages to other components of the system Additionally it manages a list of interface objects see Section 8 2 which the user can access by sending messages to them cf system commands Appendix A All modules shown in Figure 4 are interface objects their names are given in parentheses Pretty UserInterface Printer Parser Syntactical Analysis Normalizer SemAnalyzer LogicEval Translator RuleBodies Creator Algebraic Insert AlgebraicEval gebraic Inser Iterators Semantic Level NsgmlHandler OM Access DTDParser Iterators Frame Level DatabaseExport Object Manager Name Table Figure 4 Structure of the FLORID system
42. stem Recent Changes Versions 2 1 and 2 2 contain internal modifications enabling compilation with glibc6 egcs and enhanced installation and compilation features Versions 2 3 to 3 0 stepwise implemented the XML functionality for documentation see May00 1 INSTALLATION 4 1 Installation 1 1 Installation of the Source Distribution Not yet available 1 2 Installation of the Binary Distribution The binary distribution of FLORID comes as a packed and compressed file florid lt version number gt lt operating system gt tar gz In the following we refer to this file simply as florid tar gz The file is uncompressed by the command gunzip florid tar gz The resulting file florid tar has to be unpacked by entering tar xvf florid tar Now the directory florid is created It has the following subdirectories florid bin florid environment florid sgml1 florid doc florid examples florid examples tutorial The directory florid bin contains the binary florid environment contains several files defining the FLORID environment e config flp in the source of the configuration file see Section 8 4 e default his history lines to preload e flp el the emacs flp mode definition file First the FLORID configuration has to be adapted to the local system by changing to the configure directory florid environment and calling configure this generates config flp from FLORID config flp in The directory florid sgml contains seve
43. tabase for the program s semantics see FHM 00 naxos florid bin gt florid invoke FLORID from the shell This is Florid Type sys help for further information sys consult first_example flp system command to load file sys eval start evaluation of current program X fly gt yes logical query to the model computed Answer to query X fly gt yes answer set is printed X bob 1 output s printed sys end quit FLORID Bye naxos flogic bin gt In the above example FLORID entered the interactive mode after having processed the com mand line Now the prompt is displayed indicating that queries can be entered The queries starting with sys are system commands which allow user interaction with the system see Section 4 Here the program first_example f1lp is loaded by sys consult first _exa Then it is evaluated by sys eval Other queries refer to the evaluated model in this 3 RUNNING FLORID IN EMACS 7 case the answer set is printed stating that bob is the only object which flies See Section 8 1 for a detailed description of the interactive mode To leave FLORID enter sys end If FLORID is started with the option q it quits after execution of the command line instead of entering the interactive mode This is helpful if the user wants to call florid in batch mode e g from a shell script florid q test flp 3 Running Florid in Emacs Running th
44. the shell Then the file edge flp is as follows el edge 1 gt n1 2 gt n2 e2 edge 1 gt n2 2 gt n4 e3 edge 1 gt n1 2 gt n3 e4 edge 1 gt n3 2 gt n4 e5 edge 1 gt n4 2 gt n5 e6 edge 1 gt n5 2 gt n6 edge path p E P path 1 gt X 2 gt Z E edge 1 gt X 2 gt Y P path 1 gt Y 2 gt Z sys eval p el P path Every system command can occur in a program file as well Most often however commands for controlling evaluation are used in program files By using the command sys strat doIt the user can partition the program into strata by hand see Sec 4 2 This is helpful and sometimes unavoidable when negation is used Other applications e g for gaining efficiency are possible too Scenario 2 Before using a negated goal in a rule set a stratum Document this by printing a message X L gt gt Y YL L line gt gt X X reaches gt gt X X stop c nil X Y L from gt X reaches gt gt Y to gt Y X L line gt gt Y sys strat dolt sys echo Stratum c N X Z L rom gt V reaches gt gt Z to gt Z c N X Y L from gt V Y L line gt gt Z not V Z REFERENCES 35 The interface object strat is a block see Sec 4 2 By calling its method doIt the block is consulted In the case of strat the two commands sys eval and sys forgetProgram are executed thus stratifying the program References AHV95 Serge Abiteboul R
45. ttribute The interface objects can be accessed as virtual methods of sys The path expression sys objname yields the object associated with the method objname Furthermore sys objname method would invoke method on this object The existing objects can be listed by entering sys display that means sending the method display to the host object sys A new interface object that is a new method of sys is defined by a query of the form syslobjname gt expression Note that this is syntactically a query as every system command but semantically it plays the role of a fact If objname is unknown to the user interface not in the list printed after the display command a new method is added and bound to the value of expression which is an object otherwise the old value is replaced by the new one In the method definition expression may stand for e methname i e an identifier starting with lower case letter denoting a method e Integer e String e expression methname e expression methname expression expression Here are some examples for definitions of interface objects sys loops gt 3 sys filename gt config flp sys newWorld gt classOM new sys debugfile gt sys open logfile An interface object can be deleted by sys remove thisobject There are also a number of class objects available at the user interface They provide a construction kit to build a FLORID system
46. utput framewise i e every stored object has a frame which contains all its properties by sys theOM dump The OM dumping is written to a file by sys theOM saveAs String For additional output formatting see May00 The output can then be again consulted by another F Logic program For more detailed OM browsing for debugging see Section 6 1 6 Debugging Several components of the system provide a debug mode which can independently turned on or off All debug output is sent to the debug channel so it can be easily redirected see Sec 5 2 6 DEBUGGING 16 6 1 Debugging the Evaluation Of course the most important thing to debug is evaluation of programs The basic debug mode of the evaluation component theEval is enabled with the command sys theEval debugOn Then Tp applications and reached fixpoints are reported Every time a rule is matched a dot is printed So the progress of complex programs or programs dealing with large models can be followed Additionally parameters can be added to the debugOn command telling the evaluation component what to monitor program The program to evaluate is printed at the beginning This is especially useful when dealing with nested consults collecting rules and facts Also in the case of semi naive evaluation the outcome of the program transformation may be of interest dump After each Tp round the contents of the object manager is printed This makes s
47. val evaluate the current program i e calculate a model strat dolt evaluate a stratum echo print argument string break dolt stop program execution and get into interactive mode return continue program entered in interactive mode after sys break dolt end exit FLORID The OM contents can be dumped or saved sys sys theOM dump dump OM theOM saveAs String save OM to file For additional output formatting see May00 The FLORID output can be formatted and redirected using the following commands sys sys sys sys sys sys prn style instance bound html select output style prn mode poor const first best select output of internal names open lt filename gt open a FLSysOStream pointing to a file Usage sysl output gt sys open logfilestream creates an interface object output which is assigned to the stream lt channel gt setStream lt stream gt redirect lt channel gt to lt stream gt Usage sys answerChannel setStream output lt channel gt resetStream reset flq channel frq to default remove lt if object gt remove the interface object if it is a stream the corresponding file is closed The following system commands support debugging sys sys sys sys sys sys sys sys sys showProgram show current program facts and rules forgetProgram clear the current program forget IDB clear the Obje

User Manual - University of Freiburg

Contents

Download Pdf Manuals

Related Search

Related Contents