diff --git a/pyecoreocl/compiler.py b/pyecoreocl/compiler.py
index 6e0bd0d..641f09a 100644
--- a/pyecoreocl/compiler.py
+++ b/pyecoreocl/compiler.py
@@ -545,6 +545,20 @@ def rule_including(emitter, ctx):
     emitter.inline(",))")
 
 
+@call_rule
+def rule_append(emitter, ctx):
+    rule_including(emitter, ctx)
+
+
+@call_rule
+def rule_prepend(emitter, ctx):
+    emitter.inline("itertools.chain((")
+    emitter.visit(ctx.argExp())
+    emitter.inline(",), ")
+    emitter.visit(ctx.expression)
+    emitter.inline(")")
+
+
 @call_rule
 def rule_excluding(emitter, ctx):
     emitter.inline("_e for _e in ")
diff --git a/tests/test_collection_lib.py b/tests/test_collection_lib.py
index f5af9b1..b76e43c 100644
--- a/tests/test_collection_lib.py
+++ b/tests/test_collection_lib.py
@@ -157,4 +157,20 @@ class B(X):
     l = [A(), A(), B(), B()]
     assert !l->selectByType(A)->asSequence()! == l[:2]
     assert !l->selectByType(B)->asSequence()! == l[2:]
-    assert !l->selectByType(X)->asSequence()! == []
\ No newline at end of file
+    assert !l->selectByType(X)->asSequence()! == []
+
+
+def test__append():
+    assert !Set{1, 2}->append(1)->asSet()! == {1, 2}
+    assert !Set{1, 2}->append(3)->asSet()! == {1, 2, 3}
+
+    assert !Set{1, 2}->append(1)->asSequence()! == [1, 2, 1]
+    assert !Set{1, 2}->append(3)->asSequence()! == [1, 2, 3]
+
+
+def test__prepend():
+    assert !Set{1, 2}->prepend(1)->asSet()! == {1, 2}
+    assert !Set{1, 2}->prepend(3)->asSet()! == {1, 2, 3}
+
+    assert !Set{1, 2}->prepend(1)->asSequence()! == [1, 1, 2]
+    assert !Set{1, 2}->prepend(3)->asSequence()! == [3, 1, 2]
\ No newline at end of file