### M[UMPS] by Example

Approved for inclusion in a future M[UMPS] language standard as part of the library for Matrix Mathematics.

This function adds two (sparse) matrices.

```2   3   4       1   2   3       3   5   7
5   3   1   +   3   2   1   =   8   5   2
7   6   5       1   2   3       8   8   8
```

Cells that were not defined in the source matrices will not be defined in the result matrices (sparsity is retained) (a cell containing "#" means no defined value):

```#   3   4       1   2   #       1   5   4
5   #   1   +   3   #   1   =   8   #   2
7   6   #       #   2   3       7   8   3
```

Kill FIRST,SECOND
Set FIRST(1,2)=3,FIRST(1,3)=4
Set FIRST(2,1)=5,FIRST(2,3)=1
Set FIRST(3,1)=7,FIRST(3,2)=6
Set SECOND(1,1)=1,SECOND(1,2)=2
Set SECOND(2,1)=3,SECOND(2,3)=1
Set SECOND(3,2)=2,SECOND(3,3)=3

performs the math that is depicted in the second example above. The result in array RESULT will be that:

RESULT(1,1)=1, RESULT(1,2)=5, RESULT(1,3)=4
RESULT(2,1)=8, RESULT(2,2) is not defined, RESULT(2,3)=2
RESULT(3,1)=7, RESULT(3,2)=8, RESULT(3,3)=3

The MDC has approved code to approximate the return value of this function. Implementors are encouraged to provide more accurate and efficient code).