Задача 7.

Consider the following equivalence relation on the set of permutations $S_n$: $a\sim b$, if there exists a permutation $c$ such that $c^{-1}ac=b$. 1) Show that this relation is an equivalence relation; 2*) how can we easily decide whether permutations $a$ and $b$ are equivalent? Find permutations in $S_4$ which are equivalent.