Today’s Google’s doodle is about one great mathematician and one of the greatest contributors to the foundation of what today we call a computer: George Boole.

In fact, Modern Computing and Modern Electronics started to be built a long time after ‘The Laws of Thinking’ - Boole’s main work - , like a century after. Would Boole think that his work would be so important?! So important that every little action in a computer follows the **Boolean** Logic. That’s right! It was named after him.

The boolean value is fundamental for programming languages. This boolean value will tell if something is **true** or **false**, so the computer can perform actions based on these commands Additionally, there are some combinations with **true** and **false** which are very largely used, the ones that Google’s Doodle is representing. First take a look and the second G in the Doodle; it represents **x** and **y**. When the variable is showing its value it is **true**, otherwise is **false**, let’s go to the combinations:

- AND: for an ‘AND’ to produce a true value, both variables must be true. In our case, x and y must be true so the first G will be colored, otherwise ‘AND’ will produce a false value.
- XOR: for a ‘XOR’ to produce a true value, only one of the variables must be true. In our case, x must be true or y must be true, not both. So the first O will be colored, otherwise ‘XOR’ will produce a false value. X stands for exclusive.
- OR: for an ‘OR’ to produce a true value, at least one of the variables must be true. In our case, x or y must be true, or both, so the second O will be colored, otherwise ‘OR’ will produce a false value.
- NOT: differently of ‘AND’, ‘OR’ and ‘XOR’ that are binary, ‘NOT’ is an unary operation. For a ‘NOT’ to produce a true value, the variable must be false, because it is negating its own value. If the variable is true, ‘NOT’ will produce a false value. In our case, y must be false so the L will be colored, and x must be false so the E will be colored.

Here we used only two variables, but those operations can be use with as much as variables you want, like: x AND y AND z AND a…

So, because of this important contribution, Google honors the 200th George Boole’s birthday.

Well done, Google!