Comments by "" (@PunmasterSTP) on "Logic 101 (#10): Biconditional (IF AND ONLY IF)" video.

  1. Oh man, another great video! I'll be sure to keep watching them iff you post more.
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  2. How did your midterm go?
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  3. Hmmm...I think you can do this: ~(a <=> b) ~( (a => b) ^ (b=>a) ) rewrite biconditional as the conjunction of two implications ~( (~a v b) ^ (~b v a) ) rewrite implications as disjunctions (~(~a v b)) v (~(~b v a)) apply De Morgan's law (a ^ ~b) v (b ^ ~a) apply it again There's probably a more elegant way to say this, but I think you could say that either a must be true while b is false, or b must be true while a is false. So basically, they can't both be true and they both can't be false...
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