diff --git a/src/spellbind/int_values.py b/src/spellbind/int_values.py
index 2d674e8..3a1fd87 100644
--- a/src/spellbind/int_values.py
+++ b/src/spellbind/int_values.py
@@ -116,6 +116,9 @@ def __rmod__(self, other: int) -> IntValue:
     def __abs__(self) -> IntValue:
         return AbsIntValue(self)
 
+    def equals(self, other: FloatLike) -> BoolValue:
+        return CompareNumbersValues(self, other, operator.eq)
+
     def __lt__(self, other: FloatLike) -> BoolValue:
         return CompareNumbersValues(self, other, operator.lt)
 
diff --git a/src/spellbind/observable_collections.py b/src/spellbind/observable_collections.py
index f177d26..6a15977 100644
--- a/src/spellbind/observable_collections.py
+++ b/src/spellbind/observable_collections.py
@@ -7,6 +7,7 @@
 from typing_extensions import override
 
 from spellbind.actions import CollectionAction, DeltaAction, DeltasAction, ClearAction
+from spellbind.bool_values import BoolValue
 from spellbind.deriveds import Derived
 from spellbind.event import BiEvent
 from spellbind.int_values import IntValue
@@ -37,6 +38,10 @@ def length_value(self) -> IntValue: ...
     def __len__(self) -> int:
         return self.length_value.value
 
+    @property
+    def is_empty(self) -> BoolValue:
+        return self.length_value.equals(0)
+
     def combine(self, combiner: Callable[[Iterable[_S_co]], _S]) -> Value[_S]:
         return CombinedValue(self, combiner=combiner)
 
diff --git a/src/spellbind/observable_sequences.py b/src/spellbind/observable_sequences.py
index 610aa78..9c04deb 100644
--- a/src/spellbind/observable_sequences.py
+++ b/src/spellbind/observable_sequences.py
@@ -752,7 +752,7 @@ def _to_value(value: _S | Value[_S],
     if checker(value):
         return constant_factory(value)
     else:
-        return value
+        return value  # type: ignore[return-value]  # mypy raises an error since mypy 1.18.1, but that seems to be a bug https://github.com/python/mypy/issues/20330
 
 
 def _to_values(values: Iterable[_S | Value[_S]],
diff --git a/tests/test_collections/test_observable_lists/test_observable_list_is_empty.py b/tests/test_collections/test_observable_lists/test_observable_list_is_empty.py
new file mode 100644
index 0000000..0f9d3e0
--- /dev/null
+++ b/tests/test_collections/test_observable_lists/test_observable_list_is_empty.py
@@ -0,0 +1,56 @@
+from conftest import OneParameterObserver
+from spellbind.observable_sequences import ObservableList
+
+
+def test_empty_is_empty():
+    assert ObservableList([]).is_empty.value is True
+
+
+def test_one_element_is_not_empty():
+    assert ObservableList([1]).is_empty.value is False
+
+
+def test_two_elements_is_not_empty():
+    assert ObservableList([1, 2]).is_empty.value is False
+
+
+def test_adding_one_element_to_empty_list_makes_it_not_empty():
+    observable_list = ObservableList([])
+    is_empty_value = observable_list.is_empty
+    observer = OneParameterObserver()
+    is_empty_value.observe(observer)
+    observable_list.append(42)
+    assert is_empty_value.value is False
+    observer.assert_called_once_with(False)
+
+
+def test_removing_only_element_makes_list_empty():
+    observable_list = ObservableList([42])
+    is_empty_value = observable_list.is_empty
+    observer = OneParameterObserver()
+    is_empty_value.observe(observer)
+    del observable_list[0]
+    assert is_empty_value.value is True
+    observer.assert_called_once_with(True)
+
+
+def test_removing_one_element_from_two_element_list_remains_non_empty():
+    observable_list = ObservableList([1, 2])
+    is_empty_value = observable_list.is_empty
+    observer = OneParameterObserver()
+    is_empty_value.observe(observer)
+    del observable_list[0]
+    assert is_empty_value.value is False
+    observer.assert_not_called()
+
+
+def test_add_and_remove_from_empty_list():
+    observable_list = ObservableList([])
+    is_empty_value = observable_list.is_empty
+    observer = OneParameterObserver()
+    is_empty_value.observe(observer)
+    observable_list.append(1)
+    assert is_empty_value.value is False
+    observable_list.remove(1)
+    assert is_empty_value.value is True
+    assert observer.calls == [False, True]
diff --git a/tests/test_values/test_int_values/test_equal_int_values.py b/tests/test_values/test_int_values/test_equal_int_values.py
new file mode 100644
index 0000000..a6e2bcd
--- /dev/null
+++ b/tests/test_values/test_int_values/test_equal_int_values.py
@@ -0,0 +1,54 @@
+from conftest import OneParameterObserver
+from spellbind.int_values import IntVariable, IntConstant
+
+
+def test_constant_equals_constant():
+    v0 = IntConstant(0)
+    v1 = IntConstant(0)
+    equals = v0.equals(v1)
+    assert equals.value is True
+
+
+def test_constant_does_not_equal_constant():
+    v0 = IntConstant(0)
+    v1 = IntConstant(1)
+    equals = v0.equals(v1)
+    assert equals.value is False
+
+
+def test_equal_values_become_unequal():
+    v = IntVariable(0)
+    c = IntConstant(0)
+    equals = v.equals(c)
+    observer = OneParameterObserver()
+    equals.observe(observer)
+    assert equals.value is True
+    v.value = 1
+    assert equals.value is False
+    observer.assert_called_once_with(False)
+
+
+def test_unequal_values_become_equal():
+    v = IntVariable(1)
+    c = IntConstant(0)
+    equals = v.equals(c)
+    observer = OneParameterObserver()
+    equals.observe(observer)
+    assert equals.value is False
+    v.value = 0
+    assert equals.value is True
+    observer.assert_called_once_with(True)
+
+
+def test_become_unequal_and_equal_again():
+    v = IntVariable(0)
+    c = IntConstant(0)
+    equals = v.equals(c)
+    observer = OneParameterObserver()
+    equals.observe(observer)
+    assert equals.value is True
+    v.value = 1
+    assert equals.value is False
+    v.value = 0
+    assert equals.value is True
+    assert observer.calls == [False, True]