karna :flipflop: :buffsuki:@Inginsub @bajax @waifu idk what the context is but 6->7 does not always hold. More generally, a^2 = b^2 implies a = +b or a = -b. Step 7 only picks the positive root and ignores what happens when you try the other branch: you would get 2n+1=2n+1 which is trivially true so we aren't forced to accept the results of the branch taken in pic rel.
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