Unit
Let \(R\) be a ring with identity \(1 \neq 0\). We call a non-zero element \(a \in R\) a unit if there exists a non-zero element \(b \in R\) for which
\[ab=1\] (sidenote: The identity element \(1\) of \(R\) is by definition, a unit. )Let \(R\) be a ring with identity \(1 \neq 0\). We call a non-zero element \(a \in R\) a unit if there exists a non-zero element \(b \in R\) for which
\[ab=1\] (sidenote: The identity element \(1\) of \(R\) is by definition, a unit. )