: funclib.Core.Persistentǃ(funclib.Core.Reduce1(funclib.Core.conjǃ, funclib.Core.Transient(funclib.Core.HashSet()), coll));
: coll is IReduce r?funclib.Core.Persistentǃ(r.Reduce(funclib.Core.conjǃ, funclib.Core.Transient(funclib.Core.HashSet())))