also tried to work out the algebra behind his very first exercise, and got lost. For $x,y,z\in E_+$, show that $(z-x)^+ + (y-x)^+ +(2x- x\lor y$)^+\ge 0$

said: also tried to work out the algebra behind his very first exercise, and got lost. For $x,y,z\in E_+$, show that $(z-x)^+ + (y-x)^+ +(2x- x\lor y$)^+\ge 0$