...Composition is associative. If A, B, C, and D are any four objects, and <p, V, and X are morphisms from A to B, from B to C, and from C to D, respectively, then (X o ip) o <p = X o (V o <p) . (Note that each side of this equation is a morphism...
...to C to 0. D directs that fuel be unloaded in New York at storage tanks owned or leased by D. Sales from A to B, from B to C, and from C to D occur in New York; and are therefore events subject to precollected tax. Company A must precollect...
E to A, from A to B, from B to C, and from C to... 
