diff --git a/Csp/Integer/ConstrainedArray.cs b/Csp/Integer/ConstrainedArray.cs
index 4779634..bafc2a2 100644
--- a/Csp/Integer/ConstrainedArray.cs
+++ b/Csp/Integer/ConstrainedArray.cs
@@ -69,10 +69,10 @@ private Bounds<int> EvaluateBounds(ExpressionInteger left, ExpressionInteger rig
 		{
 			var elements = Elements();
 
-			return new Bounds<int>(elements.Min(), elements.Max());
-		}
+            return new Bounds<int>(elements.DefaultIfEmpty().Min(), elements.DefaultIfEmpty().Max());
+        }
 
-		private ConstraintOperationResult Propagator(ExpressionInteger left, ExpressionInteger right, Bounds<int> enforce)
+        private ConstraintOperationResult Propagator(ExpressionInteger left, ExpressionInteger right, Bounds<int> enforce)
 		{
 			var result = ConstraintOperationResult.Undecided;
 
diff --git a/Csp/Integer/ConstraintInteger.cs b/Csp/Integer/ConstraintInteger.cs
index 7eff4a5..620c9bb 100644
--- a/Csp/Integer/ConstraintInteger.cs
+++ b/Csp/Integer/ConstraintInteger.cs
@@ -98,7 +98,7 @@ public void Propagate(out ConstraintOperationResult result)
 			do
 			{
 				Propagate(enforce, out result);
-			} while ((result &= ConstraintOperationResult.Propagated) == ConstraintOperationResult.Propagated);
+			} while ((result & ConstraintOperationResult.Propagated) == ConstraintOperationResult.Propagated);
 		}
 
 		public bool StateChanged()
diff --git a/Csp/Integer/ExpressionInteger.cs b/Csp/Integer/ExpressionInteger.cs
index bc8606d..a0727a1 100644
--- a/Csp/Integer/ExpressionInteger.cs
+++ b/Csp/Integer/ExpressionInteger.cs
@@ -501,7 +501,7 @@ public class ExpressionInteger : Expression<int>
 					return new Bounds<int>
 					(
 						leftBounds.UpperBound < rightBounds.LowerBound ? 1 : 0,
-						leftBounds.LowerBound < leftBounds.UpperBound ? 1 : 0
+						leftBounds.LowerBound <= leftBounds.UpperBound ? 1 : 0
 					);
 				},
 				propagator = (first, second, enforce) =>
@@ -571,7 +571,7 @@ public class ExpressionInteger : Expression<int>
 					return new Bounds<int>
 					(
 						leftBounds.LowerBound > rightBounds.UpperBound ? 1 : 0,
-						leftBounds.UpperBound > leftBounds.LowerBound ? 1 : 0
+						leftBounds.UpperBound >= leftBounds.LowerBound ? 1 : 0
 					);
 				},
 				propagator = (first, second, enforce) =>