is_imp_onlyboolSyntax.is_imp_only : term -> bool
Tests a term to see if it is an implication.
If M has the form t1 ==> t2 then
is_imp_only M returns true. If the term is not
an implication, the result is false.
Never fails.
boolSyntax.is_imp,
boolSyntax.mk_imp, boolSyntax.dest_imp, boolSyntax.dest_imp_only,
boolSyntax.list_mk_imp,
boolSyntax.strip_imp