IDENTITY MATRICES

IDENTITY SUB-MATRIX (ISM)

IDENTITY SUB-MATRIX (ISM)

__IDENTITY MATRICES__
perform for matrix arithmetic what the number "1" performs
for the arithmetic of numbers. Below are the first four identity matrices.

An __IDENTITY SUB-MATRIX (ISM)__ is an identity matrix contained in a larger
matrix. An ISM within a Simplex Tableau may appear with it's columns
permuted (re-arranged) into an order different from the order shown above.
For example, below are 3 matrices from a discussion of SIMPLEX METHOD

In [1] the ISM is in columns x_{1} and s_{1}**;**

In [2] the ISM is in columns x_{1} and s_{2}**;**

In [3] the ISM in in columns x_{1}, x_{2}, s_{1}.

In [2] the ISM is in columns x

In [3] the ISM in in columns x