Suppose you want to prove an iff statement with an easy direction and a tough as nails, multi-page direction. The easy one goes
mfw last time i faced such an iff both were the multi-page one
Follow
actually there's a lot to be asid about "no the idea is simple and straightforward but the calculations took me a whole page"
@ZevenKorian sometimes, authors get away with "where the details are left to the reader"