dest_combTerm.dest_comb : term -> term * term
Breaks apart a combination (function application) into rator and rand.
dest_comb is a term destructor for combinations. If term
M has the form f x, then
dest_comb M equals (f,x).
Fails if the argument is not a function application.
Term.mk_comb, Term.is_comb, Term.dest_var, Term.dest_const, Term.dest_abs, boolSyntax.strip_comb