[project @ 2000-01-28 20:52:37 by lewie]

First pass at implicit parameters.  Honest, I didn't really go in *intending*
to modify every file in the typechecker... ;-)  The breadth of the change
is partly due to generalizing contexts so that they are not hardwired to
be (Class, [Type]) pairs.  See types/Type.lhs for details (look for PredType).