> that means functions have a ‘cosine similarity’ which is not remotely geometric. It obeys the normal rules you learned in geometry. For example, pick three f

> that means functions have a ‘cosine similarity’ which is not remotely geometric. It obeys the normal rules you learned in geometry. For example, pick three functions a,b,c. The functions form a triangle. The triangle obeys the triangle inequality—the distances satisfy d(a,b) ≤ d(a,c) + d(c,b). The angles of the triangle sum to 180°. This sounds an awful lot like geometry to me.