There was this company called Composition Technology [CTI] in the early '70s that typeset mathematics for various journals and textbooks using cottage-industry typists who had been trained to do markup from the manuscripts. For mathematical markup, the language they used was fairly straightforward (e.g., "sub ... base" for subscripts "div ... den ... base" for built-up fractions); overall a couple of dozen constructs of that type, each with their own spacing rules. All the common math symbols had short mnemonic names as well. The typed pages were scanned and then processed by a PDP-6 using a pile of software, eventually producing camera-ready pages on a phototypesetter. [The downfall of the company was the cost of commercial PDP-6 time; they didn't have the capital to buy their own computer. Remember, this was forty years ago.] The software knew about fonts and characters and did kerning to properly position operators, sub- and superscripts, over and under characters [e.g., accents, overbars, sum and integral limits], particularly important with the beautiful Times Italic font. AFAIK, no one does kerning anymore, and so special, more upright fonts are used to make things look less bad. CTI had software for creating new characters for the phototypesetter [mathematicians are very inventive], which used a surprisingly wierd incremental bitmap format. CTI also "invented" a new relative character position (besides sub, sup, over, under, leftsub, leftsup) called overlay, which allowed users [e.g., typists] to create useful combinations of symbols by plopping existing symbols on top of each other. CTI was owned by Alpha Industries, and when CTI failed, the technology was carefully documented and archived somewhere, presumably to remain a trade secret for eternity. On 2012-10-21 20:34, Gareth McCaughan wrote:
On Monday 22 October 2012 01:10:18 Mike Speciner wrote:
Well, maybe I'm just too fussy. (My first job, in the early '70s, was writing software to typeset mathematics beautifully, and I always thought that TeX was a big step backwards from the state of the art.) Your png looks quite similar to what I see. Should I not expect the first two 1s to be at the same height? Should I not expect the ; between 1/qz and 1/q to be vertically centered around the fraction bars so that the semicolon's dot doesn't look like a center dot? And should I not expect the spacing to be a bit looser in several places? I'm fairly sure that texify.com is not in fact running TeX; it's doing some simpler cheaper thing, probably involving MathML or something. If you typeset that same formula in TeX then ... well, actually you still get something pretty ugly, but it's ugly in quite different ways.
What was the state of the art of computerized mathematical typesetting before TeX?