strip_imp_only
boolSyntax.strip_imp_only : term -> term list * term
Iteratively breaks apart implications.
If M is of the form t1 ==> (... (tn ==> t) ...), then
strip_imp_only M returns ([t1,...,tn],t). Note that
strip_imp_only(list_mk_imp([t1,...,tn],t))
will not return ([t1,...,tn],t) if t is an implication.
Failure
Never fails.
Example
> strip_imp_only (Term `(T ==> F) ==> (T ==> F)`);
val it = ([“T ⇒ F”, “T”], “F”): term list * term
> strip_imp_only (Term `t1 ==> t2 ==> t3 ==> ~t`);
val it = ([“t1”, “t2”, “t3”], “¬t”): term list * term