On 2023-03-19 02:27, David Kra wrote: > TOBE: "Although the syntaxes differ, in GNU grep there is no difference in > available functionality between basic and extended syntaxes." I'm not a fan of "syntaxes". Although it is a word in computer science it grates in my ear because in linguistics "syntax" is a field of study and there is only one syntax just as there is only one rhetoric and there is only one logic. Anyway (to get off my soapbox :-) there's a bigger problem in the next sentence, which says, "In other implementations, basic regular expressions are less powerful." That's not true for POSIX BREs, as they have back-references, which POSIX EREs lack. (This is documented in the GNU grep manual's "Problematic Expressions" section.) And I doubt whether it's true that PCRE2 is a strict superset of EREs so we should scale the wording back a bit there too. I installed the attached doc patch, which I hope fixes these problems. (It also fixes a couple of troff typos I noticed in the neighborhood.)