xiaofei@acsu.buffalo.edu (Xiaofei Wang) (12/28/90)
I exchanged info w/ local TeXperts but there are still questions I am not able to comprehend. In TeX Book, Pg 153, it mentions that there are 16 font families [I presume this refers plain TeX]. What is the all names of fonts and their family numbers? Partial answer can be found through different channels: cmr10 \rm \fam=0 cmmi10 \mit \fam=1 cmsy10 \cal \fam=2 cmex10 \fam=3 cmti10 \it [\fam=4] cmsl10 \sl [\fam=5] cmbx10 \bf [\fam=6] cmtt10 \tt [\fam=7] Foot note: bold face italic \fam=9 (pg 156) The first 4 are provided by the TeX Book (Pg 351, 427). And the last 4's family numbers \itfam, \slfam, \bffam, \ttfam are never defined (pg 351). And I found out myself using, e.g. ``\show \itfam'' which tells me ``\itfam=\char"4''. Questions: 1. Complete answer. Why does the TeX Book does not have one? It is clear that TeXBook or TeX implimentation has *default* definitions of all family numbers of fonts. But if this is not introduced in the TeXBook, where are people supposed to look for further info? [I am advised to define my own family numbers, but I think it is better to stick to default definitions if they are there.] 2. While \itfam, for example, is never defined in the book, why \show gives an answer? [I am not comfortable with this inconsistency of TeX.] [This is independent of implementation: emTeX and our local unix TeX gives the same answer.] Why doesn't the book carry complete info? 3. While I understand that \char"4 in the phrase ``\itfam=\char"4'' means number 4. But \char"4 reminds me a character in a certain font table, but not a number. e.g. \char"4 is really a \Xi in cmr10 font table [pg 427]. I don't understand why TeX gives seemingly misleading info like ``\itfam=\char"4''. I would think ``\itfam=4'' makes more sense. 4. emTeX library has more than 16 fonts and I presume this is true for other TeX'es. Are there default definitions of family numbers of these extra fonts or I have to define myself? [This is necessary to find family numbers, see my comments at the end.] Comments: [Why I need family numbers?] While the defaut font for math is cmmi10, one can change the *ordinary text* (class 0, see pg 154) to *any* family of fonts by changing family numbers [That is why I need to find family numbers]. For example: $\fam7 \partial ABCDEFGHIJKLMNOPQRSTUVWXYZ$ $\fam2 \partial ABCDEFGHIJKLMNOPQRSTUVWXYZ$ However if one change fonts [see example below], all the characters (not only the the *regular characters*) are replaced by the corresponding characters in the font table assigned. The \partial (\char'100 of cmmi10) is replaced by @ (char'100 of cmtt10) in the first example, by \char'100 of cmsy10 in the second example. This really mess things up. \font\cmttten=cmtt10 \font\cmsyten=cmsy10 $\textfont1=\cmttten \partial ABCDEFGHIJKLMNOPQRSTUVWXYZ$ $\textfont1=\cmsyten \partial ABCDEFGHIJKLMNOPQRSTUVWXYZ$