A.9.1.1 Example 1: A simple definition.

This example shows the Common Prolog translation of the grammar shown at the top of http://cs.union.edu/~striegnk/learn-prolog-now/html/node59.html

(defgrammar gram-det

  (gram-det the)

  (gram-det a))

(defgrammar gram-n

  (gram-n woman)

  (gram-n man))

(defgrammar gram-v

  (gram-v shoots))

(defgrammar gram-np

  (gram-np (gram-det) (gram-n)))

(defgrammar gram-vp

  (gram-vp (gram-v) (gram-np))

  (gram-vp (gram-v)))

(defgrammar gram-s

  (gram-s (gram-np) (gram-vp)))

Note the use of symbols for terminals and lists for non-terminals. They all use the first form of the <lhs> and have no extra terms on the <rhs>, so all of the relations are binary.

The following will both succeed and bind ?x to the list (foo bar):

(clog:any '?x '(gram-s (a woman shoots foo bar) ?x))

(clog:any '?x '(gram-s (a woman shoots the man foo bar) ?x))

KnowledgeWorks and Prolog User Guide (Unix version) - 24 Mar 2017