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Exercise 1:

- Write a recursive function taking a natural number to a boolean
value. That value is true iff the number if even

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Exercise 2:

- State and prove the following boolean formulas:
`b1 && (~~ b2 || b3) = (b1 && ~~ b2) || (b1 && b3)`

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Exercise 3 :

Prove Peirce's law using only the rewrite command.

- Hint: use Search to find relevant lemmas about
`==>` and `~~`
- Hint: use the lemma that says
`(a || b) && a = a`

When you are done, click the Download link at the top of the page
and send us your homework by email: Assia.Mahboubi@inria.fr