# What's the shortcut?

Logic Level 2

$(A \iff B)\iff \neg (A \Rightarrow B)\Rightarrow \neg(B\Rightarrow A)$

There are two ways to prove if a statement is a tautology:
1. Build a truth table
2. Supposing the statmement is false and concluding a contradiction.

Is the mathematical statement at the top a tautology?

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