Given an m×n matrix A and a p×q matrix B, their Kronecker product C = A⊗B, also called their matrix direct product, is an (m p)×(n q) matrix with elements defined by c_αβ = a_(i j) b_(k l), where α | congruent | p(i - 1) + k β | congruent | q(j - 1) + l.