# Pastebin F0lhI2mT
infer :: Context -> LC -> Maybe Type
infer ctx (Ite t1 t2 t3) =
  case (infer ctx t1, infer ctx t2, infer ctx t3) of
    (Just Bool, Just ty2, Just ty3)
      | ty2 == ty3 -> Just ty2
      | otherwise -> Nothing
    _ -> Nothing