anchor.diff:                          else (Violation ([!!"MalformedLambdaInvocation"], "Wrong number of arguments.", originOpt), oldEnv)                        
                       | _ -> (Violation ([!!"TODO: proper violation category."], "Cannot apply a non-binding.", originOpt), oldEnv)
                   | [] -> (Unit originOpt, oldEnv)
  +            | Left (violation, _) -> (violation, oldEnv)
   
           and evalLet4 binding body originOpt env =
               let env =
  
positive.code:                  ("nth", evalNth)
                   ("product", evalProduct)]
  
          and evalIntrinsic originOpt name args env =
              match Intrinsics.TryGetValue name with
              | (true, intrinsic) -> intrinsic originOpt name args env
              | (false, _) -> (Violation ([!!"InvalidFunctionTargetBinding"], "Cannot apply a non-existent binding.", originOpt), env)
  
          and isIntrinsic name =
              Intrinsics.ContainsKey name
  
          and evalProduct originOpt name args env =
              match args with
  
negative.code: 
          and evalApply exprs originOpt env =
              let oldEnv = env
              match evalMany exprs env with
              | Right (evaleds, _) ->
                  match evaleds with
                  | head :: tail ->
                      match head with
  