Log Message:
Update mathomatic to 11.7.

Changes:

Another minor adjustment to simplify command to make everything work
just right.

Trap "derivative x" of (negative constant or zero)^x.

Solve "(constant)^y=constant" for y.

Moved all html files and the man page to subdirectory "doc".

Code cleanup.

Improved modulus solving.

Trap "x%0".  Simplify "x%inf".

Fix fraction list display of -0.

Change for better simplification.

Fix for division by roots of fractions.