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Say I have a statement A if and only if B. How do I do it without an arrow just using these symbols? Do I get a truth table? Thank you.

Math Whiz
  • 335

2 Answers2

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$A \Rightarrow B$ is the same as $¬A ∨ B$

$B \Rightarrow A$ is the same as $¬B ∨ A$

So...

$$A \Leftrightarrow B$$ is the same as $(¬A ∨ B) ∧ (¬B ∨ A)$

peter.petrov
  • 12,568
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Also, we can write it so: $$(¬A∧¬B)∨(A∧B)$$ because $A\Leftrightarrow B$ is true iff both $A$ and $B$ are true or both $A$ and $B$ are lie.