Combination Theorem for Limits of Functions/Real

Theorem
Let $X$ be one of the standard number fields $\Q, \R, \C$.

Let $f$ and $g$ be functions defined on an open subset $S \subseteq X$, except possibly at the point $c \in S$.

Let $f$ and $g$ tend to the following limits:


 * $\ds \lim_{x \mathop \to c} \map f x = l$
 * $\ds \lim_{x \mathop \to c} \map g x = m$

Let $\lambda, \mu \in X$ be arbitrary numbers in $X$.

Then the following results hold:

Also see

 * Combination Theorem for Continuous Functions