Matrix
Definition
A rectangular arrangement of numbers (elements) in rows and columns, enclosed in brackets. An m × n matrix has m rows and n columns. Matrices support addition, subtraction, and multiplication (subject to compatibility conditions).
Example
"A = [[1, 2], [3, 4]] is a 2×2 matrix. B = [[5, 6], [7, 8]]. Then A + B = [[6, 8], [10, 12]]."