Consider a sequence of non-negative simply functions $\{\phi_k(x)\}_{k=1}^\infty$ that converges point-wise to a non-negative measurable function $f$.
$$\lim_{k\rightarrow\infty}\phi_k(x)=f(x)\space\space\forall x.$$
When we actually check this with a specific example, is the following timing of steps correct?
- Fix $x$.
- Let $k$ go to infinity and see if $|\phi_k(x)-f(x)|<\varepsilon$ for arbitrarily small $\varepsilon$.
- Repeat step #1 and 2 for the entire $x$ in the domain of the function $f$.
Yes, if you remove step $1$ it checks the uniform convergence.