some TODO thoughts
fixed some accidental duplication in the summand spicing subroutine of tensoring spectral sequences
playing with the A(1) May SS demo, plus other minor tweaks. committing to handle a merge.
Merge remote-tracking branch 'origin'
hack to handle overlapping grid spaces in e.g. trigraded spectral sequences. it's a little slow.
start to keep track of, like, quarter- and half-plane spectral sequences with a generic class
also want a class for triples, since we'll be using this for the A1MSS demo
removed from leftover leibniz code
quick routine to stupidly propagate differentials en masse
include a differential propagation option that asserts all undefined terms are zero (i.e., the SS is fully defined)
get A1MSS very close to working
A1MSS is behaving less insanely, but something's still broken
A1MSS works!  it's slow, and there is some problem with displaying the EXTTerm's on page 3, but whatever!
broken attempt to make the multiplication tables indexed directly on pairs rather than description strings