Editing TeX (section)

===Mathematical spacing===
[[File:AMS Euler sample math.svg|right|280px|thumb|Mathematical text typeset using TeX and the [[AMS Euler]] font]]

Since the primary goal of the TeX language is high-quality typesetting for publishers of books, Knuth gave a lot of attention to the spacing rules for mathematical formulae.<ref>{{citation |title=Portraits in Silicon|first=Robert|last=Slater|publisher=MIT Press|date=1989|isbn=9780262691314 |page=349|url=https://books.google.com/books?id=aWTtMyYmKhUC&pg=PA349}}</ref><ref>{{citation|title=Digital Typography Using LaTeX|first1=Apostolos |last1=Syropoulos|first2=Antonis|last2=Tsolomitis|first3=Nick |last3=Sofroniou|publisher=Springer|date=2003|isbn=9780387952178 |url=https://books.google.com/books?id=LLYYisjrFdEC&pg=PA92|page=93}}</ref> He took three bodies of work that he considered to be standards of excellence for mathematical typography: the books typeset by the [[Addison-Wesley|Addison-Wesley Publishing]] house (the publisher of ''The Art of Computer Programming'') under the supervision of Hans Wolf; editions of the mathematical journal ''[[Acta Mathematica]]'' dating from around 1910; and a copy of ''[[Indagationes Mathematicae]]'', a [[Netherlands|Dutch]] mathematics journal. Knuth looked closely at these printed papers to sort out and look for a set of rules for spacing.<ref>{{Cite journal|last=Knuth |first=Donald E |title=Questions and Answers II |journal=TUGboat |volume=17 |date=1996 |pages=355–367}}</ref><ref name="DigitalTypography"/> While TeX provides some basic rules and the tools needed to specify proper spacing, the exact parameters depend on the font used to typeset the formula. For example, the spacing for Knuth's [[Computer Modern]] fonts has been precisely fine-tuned over the years and is now set; but when other fonts, such as [[AMS Euler]], were used by Knuth for the first time, new spacing parameters had to be defined.<ref>Knuth, Donald E. [http://www.tug.org/TUGboat/Articles/tb10-1/tb23knut.pdf ''Typesetting Concrete Mathematics''], TUGboat '''10''' (1989), pp. 31–36, 342. Reprinted as chapter 18 of ''Digital Typography'', pp. 367–378.</ref>

The typesetting of math in TeX is not without criticism, particularly with respect to technical details of the font metrics, which were designed in an era when significant attention was paid to storage requirements. This resulted in some "hacks" overloading some fields, which in turn required other "hacks". On an aesthetics level, the rendering of radicals has also been criticized.<ref>{{cite web |url=http://www.ntg.nl/maps/26/27.pdf |title=Math typesetting in TEX: The good, the bad, the ugly |last=Vieth |first=Ulrik |archive-url=https://web.archive.org/web/20220120120543/http://www.ntg.nl/maps/26/27.pdf |url-status=dead |archive-date=January 20, 2022}}</ref> The [[OpenType math]] font specification largely borrows from TeX, but has some new features/enhancements.<ref>{{cite web |url=http://blogs.msdn.com/b/murrays/archive/2006/09/13/752206.aspx|title=High-Quality Editing and Display of Mathematical Text in Office 2007}}</ref><ref>{{cite web |url=http://blogs.msdn.com/b/murrays/archive/2006/11/15/lineservices.aspx|title=LineServices}}</ref><ref>{{cite web|url=http://www.ntg.nl/maps/38/03.pdf |title=Map |website=ntg.nl}}</ref>