The original title is "Write your own Excel in 100 lines of F#." I don't know why the F# part was removed either. HN guidelines say "please use the original title, unless it is misleading or linkbait; don't editorialize.". Having read the article, I don't think the "in 100 lines of F#" part is misleading, nor is it Buzzfeed-style clickbait.
"in 100 lines", especially when not strictly accurate, is a nerdier version of "9 zany reasons ..." and the like. HN's title star chamber is also generally down on magic numbers in titles.
