mk_impboolSyntax.mk_imp : term * term -> term
Constructs an implication.
If t1 and t2 are terms of type
bool, then mk_imp(t1,t2) constructs the term
t1 ==> t2.
Fails if t1 and t2 are not both of type
bool.
boolSyntax.dest_imp, boolSyntax.dest_imp_only,
boolSyntax.is_imp, boolSyntax.is_imp_only,
boolSyntax.list_mk_imp