Utt ::= S Punct ;
S  ::= NP VP ;
VP ::= Cop NP ;
NP ::= PN ;
NP ::= Det CN ;
NP ::= CN ;
CN ::= CN PP ;
CN ::= AP CN ;
CN ::= N ;
AP ::= A ;
PP ::= Prep NP ;
Punct ::= "." ;
Cop ::= "is" ;
Det ::= "a" ;
Prep ::= "for" | "of" | "across" ;
PN ::= "UD" ;
N ::= "framework" | "annotation" | "grammar" | "languages" ;
A ::= "consistent" | "different" | "human" ;
