strip_imp

boolSyntax.strip_imp : term -> term list * term

Iteratively breaks apart implications.

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

See also

boolSyntax.list_mk_imp, boolSyntax.dest_imp