Issue 31: Keep track of named fraction instantiations
Project Member Reported by kevin.bi...@gmail.com, Sep 23, 2008
Join creates new NamedFraction for every node in e.g. a loop because it
doesn't track instantiations of NamedFractions.  Tracking them could avoid
the need for joining and new NamedFractions altogether.  This may also
affect monotonicity of transfer functions.