MathGloss

Let RR be a ring with multiplicative identity 11. A left RR-module MM is an abelian group (M,+)(M, +) and another operation :R×MM\cdot : R\times M \to M such that fior all r,sRr,s\in R and x,yMx,y\in M,

  1. r(x+y)=rx+ryr\cdot (x+y) = r\cdot x + r\cdot y;
  2. (r+s)x˙=rx+sx(r+s)\dot x = r\cdot x + s\cdot x;
  3. (rs)x=r(sx)(rs)\cdot x = r\cdot (s\cdot x);
  4. 1x=x1\cdot x = x.

The operation \cdot is called scalar multiplication.

Wikidata ID: Q18848