Module
Set
context | $M,R$ |
postulate | $\langle\mathcal M,\mathcal R, *\rangle \in \mathrm{module}(\mathcal M,\mathcal R)$ |
context | $\langle\mathcal M,\mathcal R, *\rangle \in \mathrm{leftModule}(\mathcal M,\mathcal R)$ |
context | $\mathcal M\in \mathrm{abelianGroup}(M)$ |
Now denote the multiplication in the ring $\mathcal R$ by “$\ \hat*\ $”.
$r,s\in R$ |
postulate | $r*s=s*r$ |
Discussion
A module is a left module with a commutative ring acting on the group.
One generally speaks of an $R$-module over $M$. Here $R$ and $M$ are just sets.
Reference
Wikipedia: Module