# Notes:Simple function approximation to a numerical function

[ilmath]\newcommand{\snaf}{\text{Snaf} } [/ilmath]

## Terminology

• [ilmath]\text{Snaf} [/ilmath] - simple numerical approximating function[Note 1]

## Raw notes

The problem is: is a [ilmath]\Snaf[/ilmath] the non-negative approximation "lemma" we first start with, or is it the thing build with two of them?

## Notes

1. Originally is was approximation function, this suggests that the [ilmath]s[/ilmath] [ilmath]\rightarrow[/ilmath] a simple function - is a numerical function. However [ilmath]s[/ilmath] is a simple numerical approximating function - ie a function that is simple and approximates something numerical. We are approximating extended real value functions, that's what we mean by "numerical function"

This note is only here for my sake. To get approximation out of my head