That ambiguity is the “uniform composition” I was talking about, which is the essence of the paradigm. But I agree that it can be a lot to keep in your head if

That ambiguity is the “uniform composition” I was talking about, which is the essence of the paradigm. But I agree that it can be a lot to keep in your head if you think about everything as a stack. That’s why I’m offering applicative syntax in Prog, because it’s far clearer in many cases than the concatenative equivalent. However, giving Prog a concatenative basis lets me do all kinds of interesting things much more easily than if I were to work from lambda calculus. With the syntactic issues taken care of by sugar, it’s a net gain. I hope you’ll see your way to trying it out one day.