Obligatory "ignore this space" : https://sacoronavirus.co.za

We hardly need to mention composite functions in general for they are merely a fact of algebra; but when we have a function that represents a shape, which might be as the shape we make by drawing lines between the stars, at times we need to let this character have a say. It might want to tell us that we don't have a right to define it mathematically; but we did so before we thought about rights. And then we find we have to make a compromise: we've just told this character that it is a mere fact of algebra. If we don't think of something quick it'll make itself look like a bracket. So we say to the character, 'we are going to apply a function to you.'

It might response, 'y'.

That suits me just fine.