Invariance of domain at least in statement seems a simple result. I mean, the first time I saw the statement I thought: "the proof can't be that bad", but when I searched for it I saw that it needs even algebraic topology to prove this result.
My doubt is: isn't there any other proof of invariance of domain that don't need to use algebraic topology? Is there some more elementary proof of this result?
Thanks very much in advance!