2004/04/24 1.13 Memory Leak and Exp problems solved:

    1. Solved a memory leak by using Scalar::Util::weaken(). This has
    reduced memory consumption when running the test cases from 130M to 37M:
    intermediate expressions are now being freed. I believe that this has
    been the source of the erratic failures appearing on various platforms
    other than my development system, as reported (most helpfully) by CPAN
    testers and an Mac OSX user, which appear to have been running out of
    memory.

    2. Corrected exp(-i)*exp(-i) which was being correctly reduced to
    exp(0), but should have been reduced further to 1, which was causing the
    multiply out of exp(i...) in cot(x) == 1/tan(x) to fail erratically.

    2004/04/24 1.12 Included PREREQ_PM in Makefile as a result of notes from
    automated CPAN testing.

    2004/04/24 1.08 Included test cases in manifest.

    2004/03/28 Split into three classes. Considerable performance
    improvements. Added standard Perl Test harness. Unfixed power() so we
    are back to constant powers.

    2004/03/14 Fixed power() so that it recognizes constant and variable
    powers. Added TODO List. Finished testSM(): new requirements in TODO.

    2004/03/13 Added change log on esteemed advice of Steffen Müller. Made
    yet another attempt to stop polynomialDivide() from producing an
    infinite series as a representation of a single term. Most of
    mathematics seems to erupt from the division of one polynomial by
    another.