Ok, I’m a little fearful to change this as it will likely just break someone else using not() as a proper function, but I’ve made not an exception so it’s basically never taken as a headless function call, but always considered to be the keyword. All the test are still passing so we’ll roll it out and see what happens

Hmm, this is one of those very ambiguous things where that code is a total legitimate method call with a singular positional parameter being passed. We basically can’t allow not() to be used as a headless method call while still being allowed to negate a parenthetical expression.