Not sure if this is related to my previous mail about negate, but that got in the way when I was trying to work out what was going on. nhc98 -T +RTS -K11048576 -RTS -c -o Mangle.T.o Mangle.lhs ==================================== Error after type deriving/checking: Type error type clash between Prelude.SR and Prelude.R when trying to apply function at 68:28 to its 1:st argument at 68:29. Type error type clash between Prelude.SR and Prelude.R when trying to apply function at 65:28 to its 1:st argument at 65:29. Lines 64 to 58 of Mangle.lhs are

-- If there is a digit then grab it get_infixes m (Just (it, -1)) (Number ([c]):ts) = get_infixes m (Just (it, ord c - ord '0')) ts -- Otherwise default to 9 get_infixes m (Just (it, -1)) ts = get_infixes m (Just (it, 9)) ts

I can put the whole file somewhere if you need it. Thanks Ian