ibc i (IBCInstance int res n ins) f
                   = return f { ibc_instances = (int, res, n, ins) : ibc_instances f }
ibc i (IBCInstance int res n ins) f
                   = return f { ibc_instances = (int, res, n, ins) : ibc_instances f }
ibc i (IBCInstance int res n ins) f
                   = return f { ibc_instances = (int, res, n, ins) : ibc_instances f }