[mathematics] An expression, named for the English mathematician George Boole (1815-1864), that results in a true or false (logical) condition. For example, in the Boolean expression “HEIGHT > 70 AND DIAMETER = 100,” all locations where the height is greater than 70 and the diameter is equal to 100 would be given a value of 1, or true, and all locations where this criteria is not met would be given a value of 0, or false.