Make ASCII art comment prettier :-)
Add new WFA::alphabet() function (with test)

Returns the set of non-epsilon symbols that appear on edges
In the WFA's HoverWeightPrinter, also allow pairs of relations

In the fancy-schmancy hover printer for WFA weights, I used to assume that the weights were BinRels (otherwise it wouldn't make sense). Now I also allow SemElemPairs where each element is a BinRel, and I render their conjunction.
Two non-failing tests & safety fix for zero weights

I thought I was getting incorrect results because zero-weight paths were being considered accepting, so I made a change to omit states reachable via zero-weight paths from eclose and wrote a couple tests. But I think the problem turned out to be elsewhere, so these changes are not so important.
Refactor WFA intersect test so I can reuse the setup later
Partial changes to incorporate accepting weights to WFAs

WFA states are no longer (well, sort of) binary accepting or not accepting, but now have an acceptingWeight(). When you add a new accepting state, it adds that state with accepting weight of 1. The semantics should be that a state is "accepting" iff its accepting weight is nonzero.

WFA determinize weight gen now has a function that will return the weight to be used on accepting states.
XFA determinization use the *current_state variables, so we need them present
XFA containment: Preliminary version
XFA containment: track pairs instead of conjunctions
XFA containment: Determinize both arguments, at least for now
XFA containment: Fix XFA intersection tests

The final check was incorrect when using the KeepBoth weight maker, as some weights were showing up as <0, x> (x!=0) which doesn't count as 0, so it was thinking that the test word was present in the intersection language when it wasn't.

(Really this is more complicated and a correct explanation involves tensor products and stuff like that and the SemElemPair has to be the way it is.)
XFA containment: working tests, finally
XFA containment: Re-enable antichains