On Wed, Apr 18, 2018 at 11:24:13PM +0300, Serhiy Storchaka wrote: > Isn't everyone expect that x*2 == x + x? Isn't this the definition of > multiplication?
I can't think of any counter-examples, but it wouldn't surprise me even a tiny bit to learn of some. > And when we have a multiplication, it can be generalized > to division. Not always. A counter-example is matrix multiplication, where multiplication is non-commutative: A*B ≠ B*A and division is not defined at all. Instead, we multiply by the inverse matrix, in the appropriate order if A*B = C then A = C*inv(B) and B = inv(A)*C And of course, when you talk about data types that aren't numeric, division makes even less sense: string multiplication means repetition, but string division has no obvious meaning. -- Steve _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/