# sigma, delta constant

If $(\sigma,\delta)$ is a skew derivation on a ring $R$, then a $(\sigma,\delta)$-constant is an element $q$ of $R$ such that $\sigma(q)=q$ and $\delta(q)=0$.

Note: If $q$ is a $(\sigma,\delta)$-constant, then it follows that $\sigma(q\cdot x)=q\cdot\sigma(x)$ and $\delta(q\cdot x)=q\cdot\delta(x)$ for all $x$ in $R$.

Title sigma, delta constant SigmaDeltaConstant 2013-03-22 11:49:38 2013-03-22 11:49:38 antizeus (11) antizeus (11) 8 antizeus (11) Definition msc 16S36