How do you write merge sort in Pascal?

To write a merge sort in Pascal, you need to implement a recursive function that divides the array into halves until single-element arrays are reached. Then, you merge these arrays back together in sorted order. Here's a basic structure:

<code class="language-pascal">procedure MergeSort(var arr: array of Integer; left, right: Integer);
var mid: Integer; begin if left < right then begin mid := (left + right) div 2; MergeSort(arr, left, mid); MergeSort(arr, mid + 1, right); Merge(arr, left, mid, right); // You need to implement the Merge procedure end; end;
</code>

You will also need to implement the Merge procedure to combine the sorted halves.