One of his expressions can be used to form a function with a value of true or false.  
He chose 1 as a logical symbol for everything in the universe, so if a set of items is x, then everything outside of x can be expressed as 1-x.  The results of one of his functions can be transformed into a logic function or logic gates, or expressed in a truth table.  One of his expressions can be used to form a function with a value of true or false.  These expressions contain operators like XOR, OR, and AND, along with set theory, to represent logical operations in mathematical form.  For ten points, name this British mathematician, whose operators are critical to computer science.
He chose 1 as a logical symbol for everything in the universe, so if a set of items is x, then everything outside of x can be expressed as 1-x.  
George {Boole}