1 files changed, 1 insertions, 1 deletions
diff --git a/sets.py b/sets.py
index 5171076..0f9e57f 100644
--- a/sets.py
+++ b/sets.py
@@ -117,7 +117,7 @@ formula = formula.replace(']sets[', '')
 rc = eval(formula)
 
 if rc.inv:
-    rc = U - rc
+    rc = U - ~rc
 
 for e in rc.elems:
     print(e)