e1 + e2 returns the element-wise sum of
two InfinitySparseMatrix objects.
If either element is inf then
the resulting element will be inf.
e1 - e2 returns the element-wise subtraction of
two InfinitySparseMatrix objects.
If either element is inf then
the resulting element will be inf.
e1 * e2 returns the element-wise multiplication of
two InfinitySparseMatrix objects.
If either element is inf then
the resulting element will be inf.
e1 / e2 returns the element-wise division of
two InfinitySparseMatrix objects.
If either element is inf then
the resulting element will be inf.