Return the value of a top-level `field = {...}` (or `field = value`) in a BibTeX entry, or None if the field is absent. Brace-aware: nested b

Normalize a venue string for comparison: drop braces, collapse whitespace, lowercase. Absorbs the cosmetic differences between hand-written BibTeX

Normalize a title for duplicate detection: lowercase, then drop everything that is not a letter or digit, so case/spacing/punctuation variants col

Return (field-name, value) of the BibTeX venue -- booktitle or journal -- or (None, None) if neither is present (i.e. an arXiv-style @misc entry).

Map arXiv id -> [filenames] and normalized-title -> [filenames] across every (parseable) file, so duplicates are detected regardless of which subs

Check if the paper contains only the right keywords. Fixes issues related to capitalization and spacing.

Filter out papers with missing key fields: TITLE, AUTHOR, VENUE, ARXIV.

Validate that BIBTEX is well-formed and stays coherent with the structured fields -- above all with VENUE. The classic bug this guards against: a