Section CostTheory.
Context `{function_cost_model}.

Theorem cost_compose_unary :
forall (A B C: Type)
(f1 : A -> B)(f2 : B ->C) c1 c2,
cost f1 c1 ->
cost f2 c2 ->
cost (fun a => f2 (f1 a)) (c1 + c2).