Needs splitting by mastery

Read­ers who come to Ar­bital pages with differ­ent lev­els of math­e­mat­i­cal back­ground re­quire differ­ent pages to ex­plain the same con­cept. Some­times a page is writ­ten in a way that seems to cater for mul­ti­ple au­di­ences (e.g. hav­ing a care­ful wordy ex­pla­na­tion de­signed for peo­ple with lit­tle back­ground, then throw­ing out for­mu­las and proofs that could only be fol­lowed by some­one with much more back­ground). In these cases, it’s of­ten best to split the page into mul­ti­ple lenses, de­signed for differ­ent math level au­di­ences.