• Thoth19@lemmy.world
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    10 个月前

    I mean it is the definition of “if and only if”. And by commutativity we also know that A iff B is equal to B iff A

      • Thoth19@lemmy.world
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        10 个月前

        Yeah if vs iff can be confusing at first. Trying to understand it with normal grammar doesn’t work right. It’s a lot more helpful to grok the symbols and so the truth tables by hand to see how they fit together