Let $A$ be a local ring with maximal ideal $m$ such that $$|A/m|=p^f$$ with $p$ prime integer. I have to prove that if $A/m^r$ is finite then $$|(A/m^r)^*|=p^{r-1}(p^f-1).$$ Could anyone give me some advice ?
2026-03-29 16:35:49.1774802149
Cardinal of power of maximal ideal
27 Views Asked by user147263 https://math.techqa.club/user/user147263/detail AtRelated Questions in RING-THEORY
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