Unset Implicit Arguments. Definition compose (A:Set) (g f:A -> A) (x:A) := g (f x). Definition thrice (A:Set) (f:A -> A) := compose A f (compose A f f).Build an expression, the normal form of which is 27, using only two occurrences of thrice, one occurrence of S, one occurrence of (0) and two jokers (symbol '_' ).