; A trivial grammar for a subset of English
S               NP VP
S               S CONJ S
NP              DETopt ADJstar N PPstar
NP              NP CONJ NP
VP              V NPopt PPstar
VP              VP CONJ VP
PP              P NP
NPopt
NPopt           NP
DETopt
DETopt          DET
PPstar          PP PPstar
PPstar
ADJstar         ADJ ADJstar
ADJstar
