Grammar rule interface (phrase)

The predicates below may be called to activate a grammar-rule set:

phrase( +RuleSet, +InputList)

  Equivalent to phrase(RuleSet, InputList, []).

phrase( +RuleSet, +InputList, -Rest)

  Activate the rule-set with given name. `InputList' is the list of tokens to parse, `Rest' is unified with the remaining tokens if the sentence is parsed correctly.