rational infinities don't compare correctly to each other
Let pinf = 1%0, and ninf = (-1)%0; then (min ninf pinf) is correctly reported as (-1)%0, but (min pinf ninf) is reported as 1%0. Similar problems exist with max, (<), (>), (<=), and (>=). The (hopefully attached) test program shows the trouble. I have checked this on both 32-bit x86 and 64-bit amd64, both with ghc 6.8.2, both linux; both show the same trouble.