diff --git a/src/Assignment3/IntSet.sc b/src/Assignment3/IntSet.sc
index 5314980..e021cb5 100644
--- a/src/Assignment3/IntSet.sc
+++ b/src/Assignment3/IntSet.sc
@@ -4,6 +4,7 @@ abstract class IntSet() {
   def foreach(f: Int => Unit): Unit
   def union(other: IntSet): IntSet
   def intersect(other: IntSet): IntSet
+  def excl(x: Int): IntSet
 }
 
 class NonEmpty(elem: Int, left: IntSet, right: IntSet) extends IntSet() {
@@ -37,6 +38,12 @@ class NonEmpty(elem: Int, left: IntSet, right: IntSet) extends IntSet() {
     base.union(this.left.intersect(other))
         .union(this.right.intersect(other))
   }
+
+  def excl(x: Int): IntSet = {
+    if (x < elem) new NonEmpty(elem, this.left.excl(x), this.right)
+    else if (x > elem) new NonEmpty(elem, this.left, this.right.excl(x))
+    else this.left.union(this.right)
+  }
 }
 
 object Empty extends IntSet() {
@@ -47,6 +54,7 @@ object Empty extends IntSet() {
   def foreach(f: Int => Unit): Unit = {}
   def union(other: IntSet): IntSet = other
   def intersect(other: IntSet): IntSet = Empty
+  def excl(x: Int): IntSet = this
 }
 
 val t1 = Empty
@@ -68,4 +76,9 @@ s.foreach(println)
 val s2 = Empty.add(3).add(4).add(6).add(2)
 
 s.union(s2)
-s.intersect(s2)
\ No newline at end of file
+s.intersect(s2)
+
+s2.excl(0)
+s2.excl(6)
+s2.excl(2)
+s2.excl(4)