Preconditions on arguments don't satisfy subsequent calls with the same precondition

[brson]

pred p(int i) -> bool { true }

fn f(int i) : p(i) -> int { i }

fn g(int i) : p(i) -> int { f(i) }

Function g doesn't typecheck because the precondition on f isn't satisfied. I would expect this to work, otherwise I can't push the responsibility for satisfying preconditions up the call stack.

[catamorphism]

Yeah, that's definitely a bug. I'll take a look.