Let R be a ring with multiplicative identity 1. A left R-module M is an abelian group (M,+) and another operation ⋅:R×M→M such that fior all r,s∈R and x,y∈M,
- r⋅(x+y)=r⋅x+r⋅y;
- (r+s)x˙=r⋅x+s⋅x;
- (rs)⋅x=r⋅(s⋅x);
- 1⋅x=x.
The operation ⋅ is called scalar multiplication.
Wikidata ID: Q18848