Poretsky's law of forms

In Boolean algebra, Poretsky's law of forms shows that the single Boolean equation ${\displaystyle f(X)=0}$ is equivalent to ${\displaystyle g(X)=h(X)}$ if and only if ${\displaystyle g=f\oplus h}$, where ${\displaystyle \oplus }$ represents exclusive or.

The law of forms was discovered by Platon Poretsky.