public static Proposition buildMemberOfProposition(Cons tree) {
    Logic.verifyNumberOfPropositionArguments(tree, 2);
    { Stella_Object collectionref = tree.rest.rest.value;

      { Surrogate testValue000 = Stella_Object.safePrimaryType(collectionref);

        if (Surrogate.subtypeOfSurrogateP(testValue000)) {
          { Surrogate collectionref000 = ((Surrogate)(collectionref));

            if (collectionref000.getStellaClass(false) != null) {
              return (Logic.buildIsaProposition(tree));
            }
          }
        }
        else if (Surrogate.subtypeOfSymbolP(testValue000)) {
          { Symbol collectionref000 = ((Symbol)(collectionref));

            if (collectionref000.getStellaClass(false) != null) {
              return (Logic.buildIsaProposition(tree));
            }
          }
        }
        else if (Surrogate.subtypeOfP(testValue000, Logic.SGT_LOGIC_DESCRIPTION)) {
          { Description collectionref000 = ((Description)(collectionref));

            if (Description.namedDescriptionP(collectionref000) &&
                NamedDescription.classDescriptionP(((NamedDescription)(collectionref000)))) {
              return (Logic.buildIsaProposition(Cons.list$(Cons.cons(Logic.SYM_STELLA_ISA, Cons.cons(tree.rest.value, Cons.cons(Cons.cons(collectionref000.descriptionSurrogate(), Stella.NIL), Stella.NIL))))));
            }
          }
        }
        else {
        }
      }
    }
    return (Logic.buildPredicateProposition(tree));
  }