diff --git a/guide/english/logic/algebra-of-logic/index.md b/guide/english/logic/algebra-of-logic/index.md
index b478a18823..e7f5ba4654 100644
--- a/guide/english/logic/algebra-of-logic/index.md
+++ b/guide/english/logic/algebra-of-logic/index.md
@@ -15,6 +15,10 @@ The three basic operations in Boolean Algebra are `AND`, `OR`, and `NOT`. Consid
- `x OR y` is true if and only if either of `x`, `y` are true. If `x`, `y` are both true, `x OR y` is still true
- `NOT x` is true if and only if `x` is false and vice versa
+`NOT` of boolean statements can be refactored to apply directly to each variable. Consider the following :
+- `NOT (x AND y) = NOT x OR NOT y`
+- `NOT (x OR y) = NOT x AND NOT y`
+
### More Information:
- The Calculus of Logic: George Boole
- Boolean algebra article: Wikipedia