diff --git a/logicPlan.py b/logicPlan.py
index a6ab1a5..4e5552d 100644
--- a/logicPlan.py
+++ b/logicPlan.py
@@ -177,7 +177,7 @@ def atLeastOne(literals: List[Expr]) -> Expr:
     True
     """
     "*** BEGIN YOUR CODE HERE ***"
-    util.raiseNotDefined()
+    return logic.disjoin(literals)
     "*** END YOUR CODE HERE ***"
 
 
@@ -189,7 +189,9 @@ def atMostOne(literals: List[Expr]) -> Expr:
     itertools.combinations may be useful here.
     """
     "*** BEGIN YOUR CODE HERE ***"
-    util.raiseNotDefined()
+
+    return logic.conjoin([ (~pair[0] | ~pair[1]) for pair in itertools.combinations(literals, 2)])
+
     "*** END YOUR CODE HERE ***"
 
 
@@ -200,7 +202,7 @@ def exactlyOne(literals: List[Expr]) -> Expr:
     the expressions in the list is true.
     """
     "*** BEGIN YOUR CODE HERE ***"
-    util.raiseNotDefined()
+    return atLeastOne(literals) & atMostOne(literals)
     "*** END YOUR CODE HERE ***"
 
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