dest_absTerm.dest_abs : term -> term * term
Breaks apart an abstraction into abstracted variable and body.
dest_abs is a term destructor for abstractions: if
M is a term of the form \v.t, then
dest_abs M returns (v,t).
Fails if it is not given a lambda abstraction.
Term.mk_abs, Term.is_abs, Term.dest_var, Term.dest_const, Term.dest_comb, boolSyntax.strip_abs