2012-09-20T07:30:05Z2012-09-20T07:30:05Zhttp://cab.unime.it/mus/id/eprint/701This item is in the repository with the URL: http://cab.unime.it/mus/id/eprint/7012012-09-20T07:30:05ZOn product of $P$ -functionsIt is shown that the $P$ -functions for the topological properties $P=T_0, T_1$, Hausdorff, regular, introduced by Pasynkov in $[P_2]$ and $P$=Urysohn. almost regular, semiregular, introduced by author and Cammaroto in [CN], are productive.G. Nordo