module Spec:Shorthand forsig..end
Specification module.type'apredicate ='a Specification.predicate
type('a, 'b)t =('a, 'b) Specification.t= {
|    | precond : | 
|    | postcond : | 
type 'a outcome = | | | Result of  | 
| | | Exception of  | 
include Specification