diff --git a/examples/projects/benchmark.lisp b/examples/projects/benchmark.lisp
index 5f19776..7588c08 100644
--- a/examples/projects/benchmark.lisp
+++ b/examples/projects/benchmark.lisp
@@ -23,6 +23,8 @@
   (test "and - true" (and 1 2 true 4) 4)
   (test "and - false" (and 1 false 2) false)
   (test "or - true" (or false false 2 false) 2)
+  (test "not - true" (not true) false)
+  (test "not - false" (not false) true)
 
   (test "if - branch 1" (if (gt 3 2) ("branch 1") ("branch 2")) "branch 1")
   (test "if - branch 2" (if (lt 3 2) ("branch 1") ("branch 2")) "branch 2")
@@ -40,6 +42,22 @@
   (test "filter" (filter (2 3 4 5 6) (λ (a) (eq 0 (mod a 2)))) (2 4 6))
   (test "reduce" (reduce (1 2 3) (λ (acc val) (add acc val)) 4) 10)
 
+  (def test-list ())
+  (test "push" (push test-list 1 2 3) (1 2 3))
+  (test "pop - return value" (pop test-list) 3)
+  (test "pop - modified list" test-list (1 2))
+
+  (def test-empty-list ())
+  (def test-list-2 (cons test-empty-list 4 5 6))
+  (test "cons - new list" test-list-2 (4 5 6))
+  (test "cons - unmodified list" test-empty-list ())
+
+  (def expected-object:x 1)
+  (def expected-object:y 2)
+  (def test-object (object "x" 1 "y" 2))
+  (test "object" test-object:x expected-object:x)
+  (test "object" test-object:y expected-object:y)
+
 ; Scope
 
   (def aaa 123)
@@ -57,4 +75,4 @@
 
 ; Interop
   (test "interop" ((of (of (js) "Math") "max") 2 4) 4)
-  (test "recursive key selector" ((of (js) "Math" "max") 2 4) 4)
\ No newline at end of file
+  (test "recursive key selector" ((of (js) "Math" "max") 2 4) 4)
diff --git a/index.html b/index.html
index 5a4b8f2..fe16f62 100644
--- a/index.html
+++ b/index.html
@@ -1211,6 +1211,14 @@ function Library (client) {
     }
     return args[args.length - 1]
   }
+  this.not = (a) => {
+    return !a
+  }
+  this.while = (fn, action) => {
+    while (fn()) {
+      action()
+    }
+  }
   this.each = (arr, fn) => { // Run a function for each element in a list.
     for (let i = 0; i < arr.length; i++) {
       const arg = arr[i]
@@ -1240,6 +1248,18 @@ function Library (client) {
   this.len = (item) => { // Returns the length of a list.
     return item.length
   }
+  this.cons = (arr, ...items) => { // Retruns a new array with the items appended.
+    return arr.concat(items)
+  }
+  this.push = (arr, ...items) => { // Appends the items into the existing list.
+    for (let i = 0; i < items.length; i++) {
+      arr.push(items[i])
+    }
+    return arr
+  }
+  this.pop = (arr) => { // Pop the last item from the list and return the item.
+    return arr.pop();
+  }
   this.first = (arr) => { // Returns the first item of a list.
     return arr[0]
   }
@@ -1278,6 +1298,13 @@ function Library (client) {
       return acc[key]
     }, h)
   }
+  this.object = (...entries) => { // Creates an object with provided entries.
+    const result = {}
+    for (let i = 0; i < entries.length; i += 2) {
+      result[entries[i]] = entries[i + 1]
+    }
+    return result
+  }
   this.keys = (item) => { // Returns a list of the object's keys
     return Object.keys(item)
   }
diff --git a/scripts/library.js b/scripts/library.js
index 465c366..5e0600b 100644
--- a/scripts/library.js
+++ b/scripts/library.js
@@ -415,8 +415,18 @@ function Library (client) {
     return args[args.length - 1]
   }
 
+  this.not = (a) => {
+    return !a
+  }
+
   // Arrays
 
+  this.while = (fn, action) => {
+    while (fn()) {
+      action()
+    }
+  }
+
   this.each = (arr, fn) => { // Run a function for each element in a list.
     for (let i = 0; i < arr.length; i++) {
       const arg = arr[i]
@@ -451,6 +461,21 @@ function Library (client) {
     return item.length
   }
 
+  this.cons = (arr, ...items) => { // Retruns a new array with the items appended.
+    return arr.concat(items)
+  }
+
+  this.push = (arr, ...items) => { // Appends the items into the existing list.
+    for (let i = 0; i < items.length; i++) {
+      arr.push(items[i])
+    }
+    return arr
+  }
+
+  this.pop = (arr) => { // Pop the last item from the list and return the item.
+    return arr.pop();
+  }
+
   this.first = (arr) => { // Returns the first item of a list.
     return arr[0]
   }
@@ -498,6 +523,14 @@ function Library (client) {
     }, h)
   }
 
+  this.object = (...entries) => { // Creates an object with provided entries.
+    const result = {}
+    for (let i = 0; i < entries.length; i += 2) {
+      result[entries[i]] = entries[i + 1]
+    }
+    return result
+  }
+
   this.keys = (item) => { // Returns a list of the object's keys
     return Object.keys(item)
   }