This is the revision history for compare in <libera.chat:#reg3x>

factoid_idsubjectcopulapredicateauthornamespace
15993 compare is https://en.wikipedia.org/wiki/Comparison_of_regular_expression_engines onlinecop <freenode.net:#regex>
15820 compare is digitok <freenode.net:#regex>
13504 compare is https://www.regular-expressions.info/refbasic.html onlinecop <freenode.net:#regex>