And they appeared under Firefox in the right form but with wrong height (taking a huge vertical space that appears as big blanks between lines).
(I did not check IE 9 ; if you observed something else with a
browser I did not mention here, you can please inform me so that I
will add the notice)
If you have not a browser giving a right display, you can still
use the pdf instead (where the display is always correct).
(There would be possible variants of calligraphic letters to use : A, B, C, R, or 𝒜, ℬ, 𝒞, ℛ or 𝔅, ℭ, ℜ, but, well, should I make copies of the same texts with different fonts ?)
The logs of this site indicate that there are some requests to
wrong urls (but do not show if they are from browsers used by
humans or from robots), especially to settheory.net/world/ and
other urls ending with /. Where do these final / come from (can
you explain if you had this problem) ? The correct url is
settheory.net/world (or if you wish, /world.htm)