331.lean:6:9-6:10: error(lean.inferBinderTypeFailed): Failed to infer type of binder `x`

Note: Because this declaration's type has been explicitly provided, all parameter types and holes (e.g., `_`) in its header are resolved before its body is processed; information from the declaration body cannot be used to infer what these values should be
331.lean:7:9-7:10: error(lean.inferBinderTypeFailed): Failed to infer type of binder `x`

Note: Because this declaration's type has been explicitly provided, all parameter types and holes (e.g., `_`) in its header are resolved before its body is processed; information from the declaration body cannot be used to infer what these values should be