Hello all,

I don't understand the underlined part in the following proof:

I think: it is open, because d_t is continous and {-1} closed, thus d_tB^-1 (-1) is closed too and the complement open. But why is it dense in R_+?

It would be great, if anyone could explain it to me.

http://img515.imageshack.us/img515/7190/beweisp.jpg

Best regards,

slabic