What is the meaning of := in mathematical notation?

[BustedBreaks]

u := -v

specifically the " := "

Here is the context. When f, g are suitably regular functions on R we can use the change of variable u:=-v etc..I should add that I came across this in a Fourier Transform book..

Thanks!

 

[Office_Shredder]

It usually means 'defined to be'.

So in this context, we know what v is, and we want to define u as a new variable. So you write u := -v to let the reader know u is being defined as -v (where v has been defined previously).

 

[BustedBreaks]

Ah... well that makes sense
thank you very much.

 

[CRGreathouse]

What, you haven't learned all half-dozen (dozen?) different symbols for "defined as" yet? :p

 

[EebamXela]

the program MathCad uses the ":=" to define things like variables and functions. perhaps you saw a document made with mathcad?