addPrototype: #Predicate derivedFrom: {Cloneable}.

_@(Root traits) predicate
[True].

m@(Method traits) as: p@(Predicate traits)
[| newP |
  newP: p derive.
  m asMethod: #predicate on: {newP traits}.
  newP
].

def@(Syntax MethodDefinition traits) predicated
[| newDef |
  newDef: (def deepCopy: def parentScope).
  newDef statements:
    ([| :tests |
       def roles with: def inputVariables do:
         [| :role :var |
           role = #[Syntax Literal for: NoRole]
             ifFalse:
               [tests nextPut:
                 `((Syntax LoadVariable from: var) `unquote predicate
                    ifFalse: [^ resend])]]
     ] writingAs: {}) ; newDef statements.
   newDef
].