ibc i (IBCClass n) f
                   = case lookupCtxtExact n (idris_classes i) of
                        Just v -> return f { ibc_classes = (n,v): ibc_classes f     }
                        _ -> ifail "IBC write failed"
ibc i (IBCClass n) f
                   = case lookupCtxtExact n (idris_classes i) of
                        Just v -> return f { ibc_classes = (n,v): ibc_classes f     }
                        _ -> ifail "IBC write failed"
ibc i (IBCClass n) f
                   = case lookupCtxtExact n (idris_classes i) of
                        Just v -> return f { ibc_classes = (n,v): ibc_classes f     }
                        _ -> ifail "IBC write failed"