### Lab02: Selection Sort (part 1) and ≤ on Answer

##### due by Monday, Feb 6, 2023

Before doing this assignment you will need to pull from the upstream repository, i.e., the course repository. Please complete the definitions/proofs in the files PnP2023/Labs/Lab02/SelectionSort.lean and PnP2023/Labs/Lab02/AnswerLE.lean. When you are done please commit and push your changes to your forked private repository and alert me on Zulip.

1. Complete the proof of remove_length_le in PnP2023/Labs/Lab02/SelectionSort.lean.

2. Complete the proof of remove_mem_length in PnP2023/Labs/Lab02/SelectionSort.lean.

3. Complete the definition of selectionSort in PnP2023/Labs/Lab02/SelectionSort.lean, including proof by termination. Do not make this a partial def. Also ensure that there is no error saying that you failed to prove termination.

4. Complete the proof of Answer.eq_of_le_le in PnP2023/Labs/Lab02/AnswerLE.lean.