#= disabled
#$ [env expansion] I don't remember what this was for, but its name (error name) was "constructor unions not unifying". (kkc: added constraints)

fn id (x)
	return x

fn uni (l asd, r asd)
	return

Callback
	Callback (Int -> Int)

ff = Callback(id)

fn f (x aaa) <= Str aaa
	fn printn (n bbb) -> bbb <= Str bbb
		println(n)
		println(x)
		return n

	uni(Callback(printn), ff)
	return

f(1)
f(True)