Every mathematician who has ever exchanged (La)TeX files by email must have noticed lines starting
¿From…
appearing in the resulting dvi or pdf file.
These charmingly infuriating lines are due (if I understand things right) to TeX’s transforming the character “>” into the inverted question mark, and to the tendency of email programs to consider that a line starting with “From” means that an included email is starting, which must be quoted with “>”. Since mathematical papers tend to have sentences like “From this, it follows that…”, this is what we end up with, unless one is careful to regularly search the document for the telltale “>From” in order to remove the offending symbol (or one gets the reflex of cleverly writing “{}From” instead of “From”, something I just learnt from a coauthor.)
But I find it ironic that computers, which can apparently spell-check documents, correct their grammar, or attempt translating them into Esperanto, are unable to understand that sentences starting with “From” might be legitimate…
