> that all its components I didn’t say all of its components, I said components making use of GPL licensed components or code. His math code could totally be

> that all its components I didn’t say all of its components, I said components making use of GPL licensed components or code. His math code could totally be licensed MIT, depending on how the program is put together. His UI code is inextricably derivative of QT though — you can’t separate the two. So even if that code itself could be licensed MIT (which is not clear to me), practically speaking, it can only be used alongside the GPL component and thus in a GPL work. In some few situations, I suppose the distinction could matter, though.