And then we went on and we said, look, if s of x can be represented as the matrix multiplication a x, the matrix vector product, and if T of x can be represented -- or the transformation T can be represented-- as the product of the matrix b with x, we saw that this thing right here -- which is of course, if we just write this way, this is equal to a times T times x, which is just b x -- we saw in multiple videos now that this is equivalent to, by our definition of matrix products, the matrix a b -- right?