I don't understand the naming and notation of this article because the author is assuming context that I don't have. Section baseline: What are N, M, K? 3 matr

I don't understand the naming and notation of this article because the author is assuming context that I don't have. Section baseline: What are N, M, K? 3 matrices or? Laid out as a flat array, or what? `c[m * N + n] += a[m * K + k] * b[k * N + n];`, ah, apparently a b and c are the matrices? How does this work? Section body: What is the mathy "C′=αC+A⋅B"? derivative of a constant is the angle times the constant plus the dot product of A and B??? Please, if you write a public blog post, use your head. Not everybody will understand your terse notes.