Adding a space in math-mode

[Joseph Turian]

Let's say I have the following formula:
$f(x) = 1 \forall x$

But this is poor, since there should be a space between 1 and the
\forall.

Is there any difference between:
$f(x) = 1\ \forall x$
and
$f(x) = 1~\forall x$

Does the '~' have a fixed length?

Joseph

[Steven Hirst]

Post by Joseph Turian
$f(x) = 1 \forall x$
But this is poor, since there should be a space between 1 and the
\forall.
$f(x) = 1\ \forall x$
and
$f(x) = 1~\forall x$
Does the '~' have a fixed length?
Joseph

~ is just a standard non-breaking space. I believe that it follows the
usual Latex formatting rules in terms of whitespace.

Steve.

[El Bandolero]

Post by Joseph Turian
$f(x) = 1 \forall x$

$f(x) = 1\, \forall x$
if you need more
$f(x) = 1 \quad \forall x$
if you need less
$f(x) = 1 \; \forall x$

HTH

[Enrico Gregorio]

Post by Joseph Turian
$f(x) = 1 \forall x$
But this is poor, since there should be a space between 1 and the
\forall.
$f(x) = 1\ \forall x$
and
$f(x) = 1~\forall x$
Does the '~' have a fixed length?

There is no difference in the final spacing, but the first one
could be split across lines.

Anyway, consider writing "$f(x)=1$, for all~$x$", unless
you are typesetting some concise table.

Ciao
Enrico

[Steven Hirst]

Post by Enrico Gregorio

Post by Joseph Turian
$f(x) = 1 \forall x$
But this is poor, since there should be a space between 1 and the
\forall.
$f(x) = 1\ \forall x$
and
$f(x) = 1~\forall x$
Does the '~' have a fixed length?

There is no difference in the final spacing, but the first one
could be split across lines.
Anyway, consider writing "$f(x)=1$, for all~$x$", unless
you are typesetting some concise table.
Ciao
Enrico

\forall is a maths notation which displays an upside down 'A' :)

S.

[Joseph Turian]

Post by Enrico Gregorio
Anyway, consider writing "$f(x)=1$, for all~$x$", unless
you are typesetting some concise table.

Agreed, this does read better.

This isn't the only case of spacing in math-mode that I need---most
notably, I want ", " in my subscripts of summations---so it was just an
example.

Thank you everyone for your helpful comments.

Joseph