mk_let : (term * term) list * term -> term
# mk_let([`x:num`,`1`],`x + 2`);; val it : term = `let x = 1 in x + 2` # mk_let([`CONS (h:bool) t`,`[F;F;F;F]`; `z:num`,`1`],`h ==> z = 2`);; val it : term = `let CONS h t = [F; F; F; F] and z = 1 in h ==> z = 2`