Flex Tutorial

INTRODUCTION TO FLEX
1.1 What is Flex?

1.1.1 What are Flex programs?

1.1.2 How does Flex relate to Prolog?

1.1.3 Constructs in Flex

1.1.4 How extendable is Flex?

1.1.5 Naming conventions in Flex

1.2 Basic Flex Constructs

1.2.1 KSL Sentences

1.2.2 Conditions and Directives

1.3 Installing and starting Flex

1.4 Important Tips

1.4.1 The Console window

1.4.2 Create a new file

1.4.3 The Run Menu

1.4.4 Analysing syntax errors

1.4.5 How are Flex programs compiled?

1.4.6 How are Flex programs executed?

1.4.7 Restarting Flex?

1.4.8 How do I stop Flex (or Prolog) running?

1.4.9 Use of semicolons

1.4.10 Use of full stop

1.4.11 Use of spaces

1.4.12 Use of quotes and apostrophes

1.4.13 Use of the $ character

1.4.14 Debugging in Flex

1.5 Useful Prolog routines

1.5.1 Prolog built-in predicates

2 STARTING PROGRAMMING

2.1 First Program

2.2 Questions and answers

2.3 Compiling and running queries

2.4 Expanding the code

2.5 Expanding the code further

3 FRAMES AND INSTANCES

3.1 Frames and Instances

3.2 Attribute Values

4 MORE ON ACTIONS

4.1 Using the student information base

4.2 Scheme for changing a student’s status and checking both the old and the new value

4.3 A special frame called ‘global’

4.4 Some aids to formatting

5 SOME TECHNICAL NOTES

5.1 Comments and punctuation

5.2 Numbers

5.3 Atoms

5.4 Byte Lists

5.5 Strings

5.6 Variables

5.7 Names

5.8 Values

6 FORWARD-CHAINING PRODUCTION RULES

6.1 Rules

6.2 Rule sets

6.3 Facts and exceptions

6.4 Groups (static)

6.5 Groups (dynamic)

6.5 Questions (dynamic)

6.6 Relations

6.7 Multiple Relations

6.8 Templates

7 PROJECTS

7.1 Saving a changed database

7.2 Changing the database at run-time

7.3 Saving the modified database

7.4 Retrieving the modified database

8 DATA DRIVEN PROGRAMMING

8.1 Launches

8.2 Constraints

8.3 Demons

8.4 Watchdogs

9 DIRECTIVES AND CONDITIONS

9.1 Directives

9.1.1 Assignments

9.1.1.1 Direct Assignments

9.1.1.2 New instances

9.1.2 Database Maintenance

9.2 Conditions

9.2.1 Equality Comparison

9.2.2 Direct Comparison

9.2.3 Relative Comparison

9.2.4 Set Membership

9.2.5 Procedure Calls

9.3 Conjunctions and Disjunctions

9.4 Context Switching

10 MISCELLANEOUS

10.1 Functions

10.2 Importing Records

11 TRAVERSING THE FRAME HIERARCHY

11.1 Inherited Values

11.2 Identification algorithm

12 TROUBLESHOOTING

13 USEFUL PROLOG ROUTINES

13.1 Listing code

13.2 Displaying values

13.3 Membership

13.4 Misc