Node:CHR Library, Next:, Previous:CHR Introductory Examples, Up:CHR



CHR Library

CHR extend the Prolog syntax by a few constructs introduced in the next sections. Technically, the extension is achieved through the user:term_expansion/2 mechanism. A file that contains a constraint handler may also contain arbitrary Prolog code. Constraint handling rules can be scattered across a file. Declarations and options should precede rules. There can only be at most one constraint handler per module.