Problem 3 Do Exercise 71 on page 46 in [EML.Chapter_4.pdf].

2

For LEAN_4 exercises in this assignment, your solutions should be restricted to

tactics and lemmas which are introduced up to the end of [MoP, Section 6.4].

We will take off points from solutions that use tactics and lemmas introduced in

[MoP, Section 6.5] and later sections or nowhere used in [MoP].

import Mathlib.Data.Real. Basic

import Library. Theory.Parity

import Library. Theory. Comparison

import Library. Theory. Prime

import Library. Tactic. Induction

import Library. Tactic. ModCases

import Library. Tactic. Extra

import Library. Tactic. Numbers

import Library. Tactic. Addarith

import Library. Tactic. Use

import Mathlib. Tactic.GCongr

import Library. Tactic. Cancel

0

In your solutions for Problem 4 and Problem 5 as LEAN_4 scripts, you may want to include the

following imports from the LEAN_4 library (possibly not all of them, but you will have to experiment

to find out if all are needed):