squeeze theorem

Proper noun

 * 1)  A theorem used to confirm the limit of a function via comparison with two other functions whose limits are known or easily computed.

Usage notes
The theorem is, supposing that


 * $$g(x) \leq f(x) \leq h(x) \, $$

and also that


 * $$\lim_{x \to a} g(x) = \lim_{x \to a} h(x) = L. \, $$

then


 * $$\lim_{x \to a} f(x) = L.$$