ex 2.93 - set up my plan
ex 2.93 - copy old rational impl
ex 2.93 - make and to-string done
ex 2.93 - enable numer / denom
ex 2.93 - 'add' ported

turns out that I SHOULD NEVER use identical names for both generic and
inner-package version, which makes nothing but confusion
ex 2.93 - `sub` done
ex 2.93 - plan updated
ex 2.93 - output demo details
ex 2.93 - expose `mul` and `div`
ex 2.93 - impl `make-polynominal`
ex 2.93 - done
ex 2.94 - start
ex 2.94 - plan
ex 2.92 - back and write some comments
ex 2.94 - some broken code .. try to debug
ex 2.94 - fix typo
ex 2.94 - use old package (w/o variable ordering)
ex 2.94 - bug fix - error on add/sub/mul...
ex 2.94 - remainder-term on termlist-sparse - done
ex 2.94 - remainder-poly - done