diff --git a/src/lib/prelude.md b/src/lib/prelude.md
index 2dc21cf..dfae095 100644
--- a/src/lib/prelude.md
+++ b/src/lib/prelude.md
@@ -1,3 +1,44 @@
 # Prelude
 
 The `Prelude` module is automatically imported and opened in all programs.
+
+### Available functions:
+
+---
+`flip f` returns function with flipped arguments
+
+`flip f x y = f y x`
+
+---
+`fst p` returns first element of a pair `p`
+
+`fst (x, _) = x`
+
+---
+`snd p` returns second element of a pair `p`
+
+`snd (_, y) = y`
+
+---
+`not b` negates boolean value `b`
+
+---
+`charListToStr xs` converts list of characters `xs` into `String`
+
+---
+`chr n` converts integer `n` to corresponding ASCII character (`0 <= n <= 256` to work properly)
+
+---
+`printStrLn`
+
+---
+`printStr`
+
+---
+`printInt` prints integer
+
+---
+`readLine` reads line of input, returns `String`
+
+---
+`exit`