let dump_doc = vcat [ppr dc, ppr dc_univ_tyvars, ppr dc_ex_tyvars,
ppr arg_tys, ppr dc_args, ppr _dc_univ_args,
ppr ex_args, ppr val_args]
let dump_doc = vcat [ppr dc, ppr dc_univ_tyvars, ppr dc_ex_tyvars,
ppr arg_tys, ppr dc_args, ppr _dc_univ_args,
ppr ex_args, ppr val_args]