= do { result@(rep_tycon, rep_tys) <- tcLookupFamInst tycon tys
; let { tvs = map (Type.getTyVar
"TcDeriv.tcLookupFamInstExact")
= do { result@(rep_tycon, rep_tys) <- tcLookupFamInst tycon tys
; let { tvs = map (Type.getTyVar
"TcDeriv.tcLookupFamInstExact")