The words are “within” and “upon.” Both are fancy versions of what they actually mean, namely “in” and “on.” For example:
This line of code can be found within that module.
Instead, how about:
This line of code can be found in that module.
We’ll skip my usual rant about using the passive; isn’t that second example better? It’s more direct, doesn’t call attention to itself.
Okay, it’s been several posts since I posted a comic, so here’s one to illustrate “upon.” My sincere thanks to Zach Weinersmith for his Saturday Morning Breakfast Cereal, (for Sept 13, 2017. You’ll have to click back to that date if you’re visiting from some day after the 13th.). It’s one of my favorite comics. They are intellectually sophisticated and funny.
The usage is in the first panel. I admit, in this context, “upon” is probably appropriate, but I think that makes the point. Are you writing an explanation for something, or are you quoting a goat skull?
So here’s the rule:
If “in” or “on” make sense, don’t use “within” or “upon.”