[tyingq]

Yes. I'm claiming that's not novel. I wouldn't try and patent a 2 stage amp with an optional 3rd stage either.

[wbl]

If it improves on existing practice even if someone would have thought of trying it it is patentable. Think of a steel with a particular alloying element: only 92 to pick from!

[jcranmer]

But what if I want to alloy steel with livermorium?