Who defined the binary system?
'Yes/No' type systems have been used for millennia eg in India,
China. I think Leibniz was the first modern mathematician to write
explicitly about '1-0' in the 18th Century, followed by George
Boole's paper on logic systems (1854?) which eventually became
known as Boolean algebra. "There are 10 types of people in the
world - those who understand binary and those who don't"