Matrix Multiplication (행렬의 곱)

Matrix Multiplication
The matrix multiplication is a binary operation that takes a pair of matrices, and produces another matrix. If @@A@@ is an @@n@@-by-@@m@@ matrix and @@B@@ is an @@m@@-by-@@p@@ matrix, the result @@AB@@ of their multiplication is an @@n@@-by-@@p@@ matrix defined only if the number of columns @@m@@ of the left matrix @@A@@ is the equal to the number of rows of the right matrix @@B@@.
In general, matrix multiplication is not commutative. More precisely, @@AB@@ and @@BA@@ need not be simultaneously defined.