F ::= EXISTS
EXISTS ::= exists var FORALL | FORALL
FORALL ::= forall var IMP | IMP
IMP ::= OR imp OR
OR ::= AND (or AND)*
AND ::= NOT (and NOT)*
NOT ::= not? GROUP
GROUP ::= PRED | opar F cpar
PRED ::= pred opar TERM (comma TERM)* cpar

TERM ::=
| var
| const
| FUN

FUN ::= var opar TERM (comma TERM)* cpar