Task: Text Simplification
Input (English): the petitions at the end of the hymn -lrb- beginning salvum fac populum tuum -rrb- are a selection of verses from the book of psalms , appended subsequently to the original hymn.
Output (English): the petitions at the end of the hymn -lrb- beginning salvum fac populum tuum -rrb- are a selection of verses from the book of psalms , later changed to the original hymn.