PDF-to-text output will not preserve the page's visual arrangement, so define what changed before comparing two extracts. Check whether text was omitted, duplicated, reordered, or altered, especially in columns and tables. Review the same source pages in a PDF viewer and note page boundaries. If cleanup removed headers or footers, confirm it did not remove similarly worded body text. A textual diff helps, but the original page remains the reference for reading order and meaning.
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