[Haskell-cafe] Linear Diaphantine equation solver bug

[John D. Ramsdell]

I uploaded a new version of the ACU unifier in package cmu.  It
includes a Linear Diaphantine equation solver that now handles
inhomogeneous equations.  What's interesting  is the algorithm is
based on a paper by Contejean and Devie.  That paper includes a proof
of correctness of their algorithm.  Yet I found an example in which
following the steps in the order they gave, the algorithm produces
extra answers.  I had to switch the order of the steps in the
algorithm to get the right answer.  I wonder if anyone else knows of
this issue.  The example is given in the module documentation on
Hackage.

John

http://hackage.haskell.org/packages/archive/cmu/1.6/doc/html/Algebra-CommutativeMonoid-LinDiaphEq.html