pg and the System 5 side of things are notable by their absence from M. Siebenmann's article. But pg appeared in System 5 release 2 or (more probably) 3 wherea

pg and the System 5 side of things are notable by their absence from M. Siebenmann's article. But pg appeared in System 5 release 2 or (more probably) 3 whereas more was 3.0BSD.