[texhax] the role of the tilde "~" in the set definition

[Lars Madsen]

Micha Hofri wrote:
> At 11:10 on 10/17/09 Lars Madsen sent:
> 
> : P. R. Stanley wrote:
> : > Hi folks
> : > Here's another one taken from the Spivey text on the z (pronounced zed)
> : > language:
> : >     \[ \{~p: PERSON | age(p) \geq 16~\} \]
> : >     A simple set definition. Any idea what the "~" is supposed to do?
> : >     
> : > many thanks
> : > Paul
> : > 
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> : it usually represents a non-breakable space
> : 
> : in math is doesn't really have any meaning, I'm guessing here that the author
> : is misusing it to provide some extra space instead of using a say \ followed
> : by a space.
> : 
> : /daleif
> 
> 
> Why is the use of tilde in math mode a misuse?  it is the most 
> keyboard-efficient of getting a controlled spacing.  I _think_ it is 
> controlled...
> 
> Just puzzled,                               --Micha Hofri
> 

well having seen people write

\begin{align*}
  A &= long equation\\
~~~~~~~~~~~~~~~~~ + B
\end{align*}

that is just nasty



/daleif