sorry before.

close this thread if it doesn't belong there

it is known, abstract algebra studying about algebraic structure. algebraic structure is non-empty set with one or more binary operation and satisfy some axioms. for example group,ring,field,etc.

its often write "let R be an algebra with relation...." or "let R be an algebra over field S"

what the meaning of algebra? what's the different from algebraic structure?

question: let R be algebra over field Q (rational), with relation $\displaystyle r=\frac{r^{n}}{n!}$ n element of natural number. R is a ring or not??