Are h(x), f(x) and g(x) three functions defined in the same domain D subset of R, excluded at most a point x0. If in each point different to x0 of the domain it is h(x)≤f(x)≤g(x), and the limit of the two functions h(x) and g(x), for x that goes to x0, is a same number l, than the limit of f(x) too for x that goes to x0 is equal l.