% EXPECT: unsat
OPTION "logic" "ALL_SUPPORTED";
IntPair: TYPE = [INT, INT];
x : SET OF IntPair;
y : SET OF IntPair;
r : SET OF IntPair;
ASSERT x = {(1,2), (3, 4)};

ASSERT y = (x  JOIN {(2,1), (4,3)});

ASSERT NOT ((1,1) IS_IN y);

CHECKSAT;