Extracts abbreviations which are preceded by the full text (e.g. 'The Quebec Xylophone Enterprise Foundation (QXEF)').
extract_validate_abbreviations(lines)Character vector of abbreviations of the form (ABC)
Lines to extract
Only 'valid' abbreviations are extracted, viz. those abbreviations of the form (ABC) where the first letters
of the preceding words
(excluding some common words like of, and, etc.) are 'a', 'b', 'c'.