@@ -0,0 +1,382 @@
+def sym_x_exist(points):%0A    l, r = min(points), max(points)%0A    mid_x = (l%5B0%5D + r%5B0%5D) / 2.0%0A    pts = set(points)%0A    for p in points:%0A        if (2 * mid_x - p%5B0%5D, p%5B1%5D) not in pts:%0A            return False%0A    return True%0A%0Atests = %5B%5D%0Atests.append(%5B(1, 2), (-1, 2), (3, 4), (-3, 4)%5D)%0Atests.append(%5B(1, 2), (-1, 2), (3, 4), (3, 5)%5D)%0A%0Afor test in tests:%0A    print sym_x_exist(test)%0A

Create SymX for Goodog