[en] The synchronization of clocks is revisited. It follows that when signals of V>c are used there is nothing paradoxical in the result t0.t0'<0. The real paradox would be to get t0.t0>0. (Author)
[pt]
A sincronizacao de relogio e reexaminada. Segue que, quando sinais de V>c sao usados, nada ha de paradoxal no resultado t0.t'0< 0. O paradoxo real seria a obtencao de t0.t0' > 0. (Autor)