So in our class, we did a proof on Kruskal's algorithm for finding Minimum Spanning Tree. Now, based on that, I have to modify it to find me a Maximum Spanning Tree. I know the idea, taking maximum-cost edges. I also have an idea why this works, because taking maximum edge from the remaining set is just like taking minimum edge from the same graph but with negative weights. My trouble is, I have no idea how to formally write down the proof knowing that Kruskal's algorithm is correct for finding Minimum spanning tree. Can someone help me and say whether I am right, and how I should write this formally, by not having to repeat the whole proof for MST and change a few things? Thanks!