Abstract: The interaction of shock waves is investigated for the following nonstrictly hyperbolic system:
u_t+(1)/2(au²+v²)_x=0 v_t+(uv)_x=0 (1 < α < 2)
The interaction of shock waves is complicated, with new types of shock waves, and new singula rities in the dependence of interaction on the relative positions of the three states separated by shock waves. Several ideas are introduced to helo organize and clarify the new phenomena.