diff --git a/Week04/functions_ayse_arsla.py b/Week04/functions_ayse_arsla.py
new file mode 100644
index 00000000..d416a2be
--- /dev/null
+++ b/Week04/functions_ayse_arsla.py
@@ -0,0 +1,64 @@
+# custom_power
+custom_power = lambda x, /, e=1: x ** e
+
+
+# custom_equation
+def custom_equation(
+    x: int = 0,
+    y: int = 0,
+    /,
+    a: int = 1,
+    b: int = 1,
+    *,
+    c: int = 1
+) -> float:
+    """
+    Calculates the custom equation.
+
+    :param x: First number.
+    :param y: Second number.
+    :param a: First exponent.
+    :param b: Second exponent.
+    :param c: Divisor.
+    :returns: The result of the equation.
+    :rtype: float
+    """
+    return (x ** a + y ** b) / c
+
+
+# fn_w_counter
+import inspect
+
+def fn_w_counter() -> tuple:
+    caller = inspect.currentframe().f_back.f_code.co_name
+
+    fn_w_counter.counter += 1
+
+    if caller in fn_w_counter.callers:
+        fn_w_counter.callers[caller] += 1
+    else:
+        fn_w_counter.callers[caller] = 1
+
+    return fn_w_counter.counter, fn_w_counter.callers.copy()
+
+
+fn_w_counter.counter = 0
+fn_w_counter.callers = {}
+
+
+# Examples
+print(custom_power(2))
+print(custom_power(2, 3))
+print(custom_power(2, e=2))
+
+print(custom_equation(2, 3))
+print(custom_equation(2, 3, 2))
+print(custom_equation(2, 3, 2, 3))
+print(custom_equation(3, 5, a=2, b=3, c=4))
+print(custom_equation(3, 5, 2, b=3, c=4))
+print(custom_equation(3, 5, 2, 3, c=4))
+
+for i in range(10):
+    fn_w_counter()
+
+print(fn_w_counter())