Classification of Binary Operations

🅟 Mar 15, 2026

  🅤 Mar 15, 2026

DEF-OCL.

Let $*$ be a binary operation on $X$. We define the following properties of $*$:

Property Condition
$A$ is closed under $*$ \(x*y\in A\)
Commutative \(x*y=y*x\)
Associative \(x*(y*z)=(x*y)*z\)
Idempotent \(x*x=x\)
Left-cancellative \(x*y=x*z\to y=z\)
Right-cancellative \(y*x=z*x\to y=z\)
Cancellative Left- and Right-cancellative
Central \((x*y)*(y*z)=y\)

If $+$ is another binary operation on $X$, we further define:

Property Condition
Left-distributive over $+$ \(x*(y+z)=x*y+x*z\)
Right-distributive over $+$ \((y+z)*x=y*x+z*x\)
Distributive over $+$ Left- and Right-distributive over $+$

The statements in the Condition column are meant to hold either for all $x\in X$; all $x$, $y\in X$; or all $x$, $y$, $z\in X$, accordingly.