subsup blobs are still laid-out crappily, but at least both
ways (a_b^c and a^b_c) of doing them parse correctly now.
At 1198 loc.
Todo: different delimiters for \left\right,
\int, \over, \matrix (!), \eqalign (!).
Aigh! Almost ran my battery down again. I keep forgetting
to plug erdos in in the morning.
Damn polymorph traps turning gnomes into bone devils.
