[texhax] The Em Rule, a Question of Style

[P. R. Stanley]

> > >Thanks for your response. So, would you say that mbox and the ~ are
> > >interchangeable in this instance?
> >
> > Without looking at the definition of \mbox one cannot be
> > certain, but I would hypothesise that \mbox creates a
> > single indivisible unit that cannot possibly be split
> > unless it is \un[*]box'd, whilst the tie ("~") simply
> > inhibits splitting at one particular place, allowing
> > other potential breakpoints to still have their
> > intended effect.
>
>A space, also ~ have stretch/shrink components. They get
>lost, if they are put in the box.
>
>"~\mbox{--}~" instead of "\mbox{ -- }" is therefore better.
>The dash creates a breakpoint by its own with the assoziated
>penalty \exhyphenpenalty. \mbox prevents the breakpoint here
>regardless of the setting of \exhyphenpenalty.
Could you provide more details on the function of \exhyphenpenalty, plese?

Cheers
Paul