Define the nondecreasing function u(x) where u(x)=1 for all x>x, and u(x)=0 otherwise We know u(x)dF(x)=1-F(x)and ∫(x)(G(x)=1-G() But if F()>G(r) then ∫(x)dG(x)>∫(x)dF(x), and thats a contradictionDefine the nondecreasing function u(x), where u(x)1 for all x   x, and u(x)0 otherwise. We know  uxdFx  1  F  x and  uxdGx  1  G  x But if F  x  G  x then  uxdGx   uxdFx, and that’s a contradiction