Nash equilibrium Pure Nash equilibrium: a joint strategy s=(s1,...,s)s.t.Vi, u(S,S)≥u(S,S) (Mixed)Nash equilibrium (NE): a product distribution p=p1×..×Pst.i,s,' Es-plu(s,s】≥Es-puS,slNash equilibrium ◼ Pure Nash equilibrium: a joint strategy s = (s1 , …, sn ) s.t. i, ui (si ,s-i ) ≥ ui (si ’,s-i ) ◼ (Mixed) Nash equilibrium (NE): a product distribution p = p1  …  pn s.t. i,si ’ Es←p [ui (si ,s-i )] ≥ Es←p [ui (si ’,s-i )]