dest_res_abstractres_quanLib.dest_res_abstract : term -> (term # term # term)
Breaks apart a restricted abstract term into the quantified variable, predicate and body.
dest_res_abstract is a term destructor for restricted
abstraction:
dest_res_abstract "\var::P. t"
returns ("var","P","t").
Fails with dest_res_abstract if the term is not a
restricted abstraction.