(Apologies for the triviality of this question; nevertheless, it's been bugging me and presumably people here will be able to answer it...)It seems that it has become popular in recent years to write the names of complexity classes in a sans serif font (see e.g. these two papers). My question is: where does this notation come from? In particular, what is the first occurrence of the use of this notation in the literature?The paper Algorithms for Boolean Function Query Properties by Scott Aaronson (SIAM Journal on Computing 32(5):1140-1157, 2003; the arXiv version dates back to 2001) uses this notation, but is there anything earlier?
First use of sans serif for complexity classes
cc.complexity theory;soft question;ho.history overview