In Boolean algebra, the algebraic normal form, ring sum normal form, Zhegalkin normal form, or Reed–Muller expansion is a way of writing propositional logic formulas in one of three subforms: The entire formula is purely true or false: 1 {\displaystyle 1} 0 {\displaystyle 0} One or more variables are combined into a term by AND, then one or more terms are combined by XOR together into ANF. Wikipedia