Is it possible to perform supremum with two parameters in the same function?

[St41n]

Can I do this:

sup_(x,y) f(x,y) = sup_y sup_x f(x,y) ?

 

[WannabeNewton]

Yes. Proof: http://math.stackexchange.com/questions/53794/simple-question-the-double-supremum

 

[St41n]

Great thanks for quick reply!