(defparameter *grammar1*
  '((sentence -> (noun-phrase verb-phrase))
    (noun-phrase -> (Article Noun))
    (verb-phrase -> (Verb noun-phrase))
    (Article -> the a)
    (Noun -> man ball woman table)
    (Verb -> hit took saw liked))
  "A grammar for a trivial subset of English.")

(defparameter *grammar1*
  '((sentence -> (noun-phrase verb-phrase))
    (noun-phrase -> (Article Adj* Noun PP*) (Name) (Pronoun))
    (verb-phrase -> (Verb noun-phrase PP*))
    (PP* -> () (PP PP*))
    (Adj* -> () (Adj Adj*))
    (PP -> (Prep noun-phrase))
    (Prep -> to in by with on)
    (Adj -> big little blue green adiabatic)
    (Article -> the a)
    (Name -> Pat Kim Lee Terry Robin)
    (Noun -> man ball woman table)
    (Verb -> hit took saw liked)
    (Pronoun -> he she it these those that)))

(defparameter *grammar2*
	'((Sentence -> (Nounphrase Verbphrase))  
	 (Nounphrase -> (Boy))              
	 (Nounphrase -> (Girl))           
	 (Boy -> john ajit)
	 (Girl -> pima barkha)
	 (Verbphrase -> (Verb Modlist Adverb with  Nounphrase))
	 (Verb -> runs  walks )                 
	 (Modlist ->  () (very Modlist))
	 (Adverb -> (quickly  slowly))))