diagrams/diagrams-core — pull request #31 by mgsloan (2012-10-30 10:20:46+00:00)
Title: Add envelopeS / envelopeSMay for querying scalar displacements from envelopes

I realize these shouldn't be encouraged, but they seem potentially useful!

Discussing the "intrudeEnvelope" in the haddocks led to figuring out how to express surprise at the fact that "envelopeS v x - envelopeS (negateV v) x < 0" is possible.