It's curious how "when b is <0" was considered okay scientific French, but in English these days it looks terrible and is written as "when b<0".
See https://cegepadistance.ca/sous-site/En_route_vers_la_reussit... to see that it is still how it is used in French today.
[1] http://www.math.washington.edu/~lind/Resources/Halmos.pdf