strip_pabs : term -> term list * term
STRUCTURE
LIBRARY
pair
SYNOPSIS
Iteratively breaks apart paired abstractions.
DESCRIPTION
strip_pabs "\p1 ... pn. t" returns ([p1,...,pn],t). Note that
   strip_pabs(list_mk_abs([p1,...,pn],t))
will not return ([p1,...,pn],t) if t is a paired abstraction.
FAILURE
Never fails.
SEEALSO
HOL  Kananaskis-14