7 CHR: Constraint Handling Rules

This chapter is written by Tom Schrijvers, K.U. Leuven for the hProlog system. Adjusted by Jan Wielemaker to fit the SWI-Prolog documentation infrastructure and remove hProlog specific references.

The CHR runtime environment using in SWI-Prolog is written by Christian Holzbaur and Tom Schrijvers while the compiler is written by Tom Schrijvers. Both are integrated with SWI-Prolog and licenced under compatible conditions with permission from the authors.

• 7.1 Introduction
• 7.2 Syntax and Semantics
  • 7.2.1 Syntax
  • 7.2.2 Semantics
• 7.3 CHR in SWI-Prolog Programs
  • 7.3.1 Embedding in Prolog Programs
  • 7.3.2 Compilation
• 7.4 Debugging
  • 7.4.1 Ports
  • 7.4.2 Tracing
  • 7.4.3 CHR Debugging Predicates
• 7.5 Examples
• 7.6 Compatibility with SICStus CHR
• 7.7 Guidelines