let (conv_tcs, keep_tcs) = classifyTyCons cs groups
keep_dcs = concatMap tyConDataCons keep_tcs
zipWithM_ defTyCon keep_tcs keep_tcs
zipWithM_ defDataCon keep_dcs keep_dcs
let (conv_tcs, keep_tcs) = classifyTyCons cs groups
keep_dcs = concatMap tyConDataCons keep_tcs
zipWithM_ defTyCon keep_tcs keep_tcs
zipWithM_ defDataCon keep_dcs keep_dcs