• Boinkage@lemmy.world
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          10 months ago

          Substitute common sense terms. If I say “if it is an apple, it is a fruit”, does it then follow that a thing is a fruit if and only if it is an apple? No. Lots of other things are fruit without being an apple.

          • Rhynoplaz@lemmy.world
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            10 months ago

            Better read that one again.

            “If B then A” … “B if and only if A”?

            If Apple then fruit. Is Apple ONLY if it’s a fruit.

            This one actually checks out.

        • Casey_Masterpiece@lemmy.world
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          10 months ago

          If B then A is the same as if X then Y is the same as if A then B. They are saying it’s the same as the OP. Changing the letters around doesn’t change the meaning since the letters are just placeholders.

          Now if you said If A then B AND If B then A as one it wouldn’t be the same because A and B would have to keep the same meaning.