add a comment |. up vote 1 down vote. If a game has a value, it need not to have a mixed strategy Nash equilibrium. In the Von Neumann's Minimax theorem stated above, it is assumed that, for each player, the set of mixed strategy best responses is nonempty given the other player's mixed strategy.
Not all RNA viruses are retroviruses, e.g., the measles virus and flu virus are RNA viruses, but not retroviruses. There are three families of retroviruses: oncoviruses (causing cancer), lentiviruses (slow viruses, of which HIV is one), and foamy viruses or spumaviruses (about which much less is known).
Coronaviruses are species of virus belonging to the subfamily Coronavirinae in the family Coronaviridae, in the order Nidovirales. Coronaviruses are enveloped viruses with a positive-sense single-stranded RNA genome and with a nucleocapsid of helical symmetry.