intersection of enclosures

[Mark S. Miller <mark>]

I like your new definition of intersect.  I was taken aback for a
moment by it's non-commutativity, but this form is more useful.  Why
is it a function instead of a message send.  Now that the left
argument also provides the reference dsp (and so is more "important"
than the right argument), it'd make even more sense to have it be the
message receiver.

   Date: Mon, 16 Oct 89 19:29:41 PDT
   From: tribble (Eric Dean Tribble)

   The new definition of intersect allows me to apply operations to an
   enclosure that always produce results in the same coordinate system.
   I think unionWith() should have the same property (commutative only
   wrt the enclosures defined region).

Do you mean superUnion?  unionWith is (should be?) only defined for
sets.  If you mean superUnion, I agree.