If the current trend toward relaxation of concealed-weapons laws continues, soon the most important gun restrictions may involve destinations: the states will probably allow various venues—public gathering places, offices, stores—to ban firearms on the premises. The only problem will be how to know who is packing heat.

K-theory was developed by Atiyah and Hirzebruch in the 1960s based on work of Grothendieck in algebraic geometry. It was introduced as a tool in C^*-algebra theory in the early 1970s through some specific applications described below. Very briefly, K-theory (for C^*-algebras) is a pair of functors, called K₀ and K₁, that to each C^*-algebra A associate two Abelian groups K₀(A) and K₁(A).

She was a modern woman. Rochelle! I hear my grandma's taunt. Imagine Rochelle! And then in Yiddish: Rachel is not good enough for her.

Those who suffer enochlophobia, demophobia or ochlophobia–the fear of crowds–are not being entirely irrational.