Deletion of Richard Johnsonbaugh

Comment: per #C4 and . I agree that his research doesn't seem to have had much impact, but that's a different criterion, and failing it does not prevent achieving notability some other way. It's hard to count exactly how many books he has because some of them (such the ones with "programming" in the title) seem to have overlapping content, but he has at least four distinct clusters of textbooks. I found and added to the article five published reviews of three of these, enough I think for . And the ''Discrete Mathematics'' book in particular has gone through eight editions from its original 1984 publication to its most recent in 2018, and has been translated into Spanish, weak but persuasive evidence that it is widely used (#C4). I also ran a Google search for "Johnsonbaugh" "syllabus" site:.edu -site:depaul.edu (to find other universities using his textbooks) and found over 500 hits
Stance: keep
Cited policy: Wikipedia:Notability (WP:PROF||WP:AUTHOR||WP:AUTHOR||WP:PROF)