# What does this notation mean?

1. Jun 21, 2009

### hawkingfan

Hey dudes, I'm trying to understand the proofs about IVPs in the appendix of my differential equations book but I can't understand this notation that says c = min {a, b/M}.

What is that notation supposed to mean? I'm guessing that it stands for minimum value between a and b/m. (a is associated with the x axis and b/M is associated with the y axis based on the picture of the graph in the book) I'm just beginning to study real analysis so I haven't seen this notation yet.

2. Jun 21, 2009

### nicksauce

Yes it just means to take the minimum value between a and b/M.

In general x = min{y1,y2,y3,...,yn} means to take the minimum value from the set {y1,y2,y3,...,yn}.

3. Jun 21, 2009

### Hurkyl

Staff Emeritus
"min S" is the element of S that is less than every other element -- it's minimum.

(the domain of "min" consists only of those ordered sets with a minimum. In other words, if S doesn't have a minimum, then "min S" is undefined)