 { f ^{\mathrm{in}}}(x,v)\,{ \mathrm{d}(x,v)}} \\ &\leq { \int _{{{{\bf}R}}^d \times {{{\bf}R}}^d}\!\!\! [({ \rho ^\varepsilon _0})^0 + |v|^0] { f ^{\mathrm{in}}}(x,v)\,{ \mathrm{d}(x,v)}}.\end{aligned}$$ 