## Binary operation

### Set

context | $X$ |

definition | it $\equiv X\times X\to X$ |

#### Discussion

Also called “law of composition”.

It's is a binary function with which takes elements of $X$ to an element of $X$ itself.

#### Reference

Wikipedia: Binary operation

context | $X$ |

definition | it $\equiv X\times X\to X$ |

Also called “law of composition”.

It's is a binary function with which takes elements of $X$ to an element of $X$ itself.

Wikipedia: Binary operation