So I've had fun tinkering with my lambda-like language. I moved on to try to introduce scoping, but I'm having some trouble. I've attached a simplified example. Compiling as-is, the test outputs what I would expect. It seems like the LookupSymbol transform works brilliantly, so symbol lookup is a go. However, convincing the grammar to match an expression that invokes the AddScope transform seems more difficult. Commenting the #if clause results in an error about converting a Wrapper<...> to a shared_ptr<Base> which I can only guess means the grammar is not matching the proto expression. I've tried all sorts of different things. I don't think the UnaryPassThrough transform should be neccessary, but maybe it does't hurt either. With or without it, the error is the same. What am I missing here? Thanks! -Dave