Another day, another Google Doodle.

This time round, users are greeted by are series “xs” and “ys” underneath each letter, which light up in accordance to the rule of logic it displays.

This is a hat tip to mathematician George Boole, whose system of logic – Boolean algebra – was a building block of the digital age.

His theory proved to be the genesis of binary code, which is based on a basic distinction between yes and no or true and false.

To commemorate the English mathematician’s 200th birthday, Google’s homepage uses Boolean algebra to dictate which letter of its logo flashes up.

For example, when “x and y” light up where the second “g” should be, the first “g” lights up – also with “x and y” under it – as well as the second “o”, which has “x or y” under it.

Various combinations of this occur as either “x”, “y” or “x and y” appear in the second “g”.

This system uses what are known as logic gates, an idea inspired by Boole’s work.

George Boole was born in England but spent much of his academic career at Cork university in Ireland, introducing his algebra in an 1847 book, then further outlined in a second 1854 book.

He died aged 49 in 1864.

The potential of his theory was realised by Claude Shannon in a 1937 thesis, where his algebra was applied to help power electric circuits – an early precursor to the technological revolution.