ppr_co p (TcLRCo lr co)       = pprPrefixApp p (ppr lr) [pprParendTcCo co]
ppr_co p (TcLRCo lr co)       = pprPrefixApp p (ppr lr) [pprParendTcCo co]
ppr_co p (TcLRCo lr co)       = pprPrefixApp p (ppr lr) [pprParendTcCo co]