Define x♢y to be max(x,y) for all real numbers x and y. Which of the following statements is not true?
x♢y=y♢x for all x and y
(x♢y)♢z=x♢(y♢z) for all x,y,z
x♢0=x for all x
x♢x=x for all x
If x♢y=y, then x≤y
