reject negative inv.a
Turns out we _can_ create a (only very very slightly) negative a term
when inverting a profile that passes our sanity tests.
Reject them like we do in fitting. Was thinking about nudging it up to
0, but that would imply some strange things, like x not mattering...
Reviewed-by: Brian Osman <email@example.com>
Commit-Queue: Mike Klein <firstname.lastname@example.org>
4 files changed