One of the amazing features of the World's first BASIC implementation from the Dartmouth College
was the ability to manipulate arrays as matricies. The 1960's are going farther and farther, at the age of Scilab, Octave and other mature numerical computations packages who can be impressed by the matrix-able BASIC. But isn't it fun when small 8-bit uC board can do what mainframes from 1960's can?
Terminal-BASIC supports these matrix operations. Main difference is that Darthmouth BASIC ignores 0-row and 0-column, making array definition more informative. DIM(3,3) defines 4x4 array, but it was used as 3x3 matrix in matrix operations. Terminal-BASIC uses all rows and columns, so DIM(3,3) defines 4x4 array, which can be used as 4x4 matrix.