Anyone help give a counterexample when $\inf_{x∈X}⁡(\sup_{y∈Y}⁡F(x,y) )\le \sup_{y∈Y}⁡(\inf_{x∈X}⁡F(x,y) )$ is false
An example of a function which satisfies $\sup_{y}\inf_{x}f(x,y)<\inf_{x}\sup_{y}f(x,y)$