
; Grammar source file

; Rule format is:-

; <rule>	::= ( <lhs> . <rhs> )
; <lhs>		::= <symbol>
; <rhs>		::= <nil> | ( <seq> )
; <seq>		::= <node> | <node> <seq> 
; <node>	::= <self> | <alts> | <star> | <opts>
; <self>	::= ( self . <category> )
; <alts>	::= ( alts . <rhs> ... <rhs> )
; <star>	::= ( star . <rhs> )
; <opts>	::= ( opts . <rhs> )

; <category>	::= ( <symbol> . <features> )
; <features>	::= <nil> | <feature> ... <feature>
; <feature>	::= <symbol> | ( <function> . <value> )
; <function>	::= ( <variable> ) | ( <variable> <symbol> ... <symbol> )
; <variable>	::= up | down
; <value>	::= <function> | <symbol> | <number>


(AP (SELF A)) 
(NP (SELF N)) 
(NP (SELF AP) (SELF N)) 
(P (SELF PP)) 
(NP (SELF PRON)) 
(S (SELF NP) (SELF VP)) 
(VP (SELF V) (SELF NP)) 
(VP (SELF V) (SELF VP)) 