it's ok now. thank you.

the answers of the last two tests are wrong, please check it!

I do not believe the answer given in test 3 of the Test Suite is correct. In test 3 there are not any positive elements above the main diagonal, so based on the instruction we must find the product of an empty set. An empty set is not numerically identical to zero. Just as a set containing two numbers (e.g. {53, 58}) is not numerically equal to two.   The product of an empty set should be 1, as respected by MATLAB (see Solution 1574245), and also explained at https://en.wikipedia.org/wiki/Empty_product .   —DIV