diff --git a/immutable.go b/immutable.go
index 4a42e33..e43bc70 100644
--- a/immutable.go
+++ b/immutable.go
@@ -752,17 +752,6 @@ func (m *Map[K, V]) Set(key K, value V) *Map[K, V] {
 	return m.set(key, value, false)
 }
 
-// SetMany returns a map with the keys set to the new values. nil values are allowed.
-//
-// This function will return a new map even if the updated value is the same as
-// the existing value because Map does not track value equality.
-func (m *Map[K, V]) SetMany(entries map[K]V) *Map[K, V] {
-	for k, v := range entries {
-		m = m.Set(k, v)
-	}
-	return m
-}
-
 func (m *Map[K, V]) set(key K, value V, mutable bool) *Map[K, V] {
 	// Set a hasher on the first value if one does not already exist.
 	hasher := m.hasher
@@ -1641,14 +1630,6 @@ func (m *SortedMap[K, V]) Set(key K, value V) *SortedMap[K, V] {
 	return m.set(key, value, false)
 }
 
-// SetMany returns a map with the keys set to the new values.
-func (m *SortedMap[K, V]) SetMany(entries map[K]V) *SortedMap[K, V] {
-	for k, v := range entries {
-		m = m.Set(k, v)
-	}
-	return m
-}
-
 func (m *SortedMap[K, V]) set(key K, value V, mutable bool) *SortedMap[K, V] {
 	// Set a comparer on the first value if one does not already exist.
 	comparer := m.comparer
diff --git a/sets.go b/sets.go
index 28f888d..d610c15 100644
--- a/sets.go
+++ b/sets.go
@@ -14,31 +14,23 @@ type Set[T comparable] struct {
 // Default hasher implementations only exist for int, string, and byte slice types.
 // NewSet can also take some initial values as varargs.
 func NewSet[T comparable](hasher Hasher[T], values ...T) Set[T] {
-	s := Set[T]{
-		m: NewMap[T, struct{}](hasher),
-	}
+	m := NewMap[T, struct{}](hasher)
 	for _, value := range values {
-		s.m = s.m.set(value, struct{}{}, true)
+		m = m.set(value, struct{}{}, true)
 	}
-	return s
+	return Set[T]{m}
 }
 
-// Set returns a set containing the new value.
+// Add returns a set containing the new value.
 //
 // This function will return a new set even if the set already contains the value.
-func (s Set[T]) Set(values ...T) Set[T] {
-	for _, value := range values {
-		s.m = s.m.Set(value, struct{}{})
-	}
-	return s
+func (s Set[T]) Add(value T) Set[T] {
+	return Set[T]{s.m.Set(value, struct{}{})}
 }
 
 // Delete returns a set with the given key removed.
-func (s Set[T]) Delete(values ...T) Set[T] {
-	for _, value := range values {
-		s.m = s.m.Delete(value)
-	}
-	return s
+func (s Set[T]) Delete(value T) Set[T] {
+	return Set[T]{s.m.Delete(value)}
 }
 
 // Has returns true when the set contains the given value
@@ -127,31 +119,23 @@ type SortedSet[T comparable] struct {
 // exist for int, string, and byte slice keys.
 // NewSortedSet can also take some initial values as varargs.
 func NewSortedSet[T comparable](comparer Comparer[T], values ...T) SortedSet[T] {
-	s := SortedSet[T]{
-		m: NewSortedMap[T, struct{}](comparer),
-	}
+	m := NewSortedMap[T, struct{}](comparer)
 	for _, value := range values {
-		s.m = s.m.set(value, struct{}{}, true)
+		m = m.set(value, struct{}{}, true)
 	}
-	return s
+	return SortedSet[T]{m}
 }
 
-// Set returns a set containing the new value.
+// Add returns a set containing the new value.
 //
 // This function will return a new set even if the set already contains the value.
-func (s SortedSet[T]) Set(values ...T) SortedSet[T] {
-	for _, value := range values {
-		s.m = s.m.Set(value, struct{}{})
-	}
-	return s
+func (s SortedSet[T]) Add(value T) SortedSet[T] {
+	return SortedSet[T]{s.m.Set(value, struct{}{})}
 }
 
 // Delete returns a set with the given key removed.
-func (s SortedSet[T]) Delete(values ...T) SortedSet[T] {
-	for _, value := range values {
-		s.m = s.m.Delete(value)
-	}
-	return s
+func (s SortedSet[T]) Delete(value T) SortedSet[T] {
+	return SortedSet[T]{s.m.Delete(value)}
 }
 
 // Has returns true when the set contains the given value
diff --git a/sets_test.go b/sets_test.go
index 5a83eb9..ca3aa3d 100644
--- a/sets_test.go
+++ b/sets_test.go
@@ -6,8 +6,8 @@ import (
 
 func TestSetsPut(t *testing.T) {
 	s := NewSet[string](nil)
-	s2 := s.Set("1").Set("1")
-	s2.Set("2")
+	s2 := s.Add("1").Add("1")
+	s2.Add("2")
 	if s.Len() != 0 {
 		t.Fatalf("Unexpected mutation of set")
 	}
@@ -34,7 +34,7 @@ func TestSetsPut(t *testing.T) {
 
 func TestSetsDelete(t *testing.T) {
 	s := NewSet[string](nil)
-	s2 := s.Set("1")
+	s2 := s.Add("1")
 	s3 := s.Delete("1")
 	if s2.Len() != 1 {
 		t.Fatalf("Unexpected non-mutation of set")
@@ -52,7 +52,7 @@ func TestSetsDelete(t *testing.T) {
 
 func TestSortedSetsPut(t *testing.T) {
 	s := NewSortedSet[string](nil)
-	s2 := s.Set("1").Set("1").Set("0")
+	s2 := s.Add("1").Add("1").Add("0")
 	if s.Len() != 0 {
 		t.Fatalf("Unexpected mutation of set")
 	}
@@ -86,7 +86,7 @@ func TestSortedSetsPut(t *testing.T) {
 
 func TestSortedSetsDelete(t *testing.T) {
 	s := NewSortedSet[string](nil)
-	s2 := s.Set("1")
+	s2 := s.Add("1")
 	s3 := s.Delete("1")
 	if s2.Len() != 1 {
 		t.Fatalf("Unexpected non-mutation of set")