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- Proof of associativity of GCD? 3 answers
Prove that for all integers $r, s$ and $t$, that $\gcd(\gcd(r, s), t) = \gcd(r, \gcd(s, t))$.
I am stuck in this proof. I have tried using Bézout's Lemma but I have no idea how to proceed further.
Any help would be appreciated.