strip_imp : term -> term list * term

SYNOPSIS
Iteratively breaks apart implications.

DESCRIBE
If M is of the form t1 ==> (... (tn ==> t) ...), then strip_imp M returns ([t1,...,tn],t). Note that
   strip_imp(list_mk_imp([t1,...,tn],t))
will not return ([t1,...,tn],t) if t is an implication.

FAILURE
Never fails.

EXAMPLE
- strip_imp "(T ==> F) ==> (T ==> F)";;
> val it = (["T ==> F"; "T"], "F") : term list * term

- strip_imp (Term `t1 ==> t2 ==> t3 ==> ~t`);
> val it = ([`t1`, `t2`, `t3`, `t`], `F`) : term list * term

SEEALSO  list_mk_imp,   dest_imp

HOL  Kananaskis 0