| MQSubset of mqlist * mqlist (* the two lists denote two sets, the 1st subset of the 2nd *)
and mqlist =
- | MQReference of mqref (* reference *)
- | MQPattern of mqtref (* pattern *)
+ | MQReference of mqref list (* reference list *)
+ | MQPattern of mqtref list (* pattern list *)
| MQListLVar of mqlvar (* lvar *)
| MQListRVar of mqrvar (* rvar *)
| MQSelect of mqrvar * mqlist * mqbool (* rvar, list, boolean *)