I'm pracitcing exams towards finals,
Given an undirected graph $G(V,E)$ , we denote 2 MST $T,T'$ neighbours if by deleting one edge from $T$ and add another one we get $T'$.
Prove : for every 2 distinct MST $T,T'$ there is a sequence of $k$ MST's such that every 2 MST's $T_i,T_i+1$(+1 on the index) in the list are neighbours and at the end of the sequence we get $T$
$T' = T_1,T_2,T_3,\ldots,T_k=T$
hope to get help.