# [texhax] the \let command

tom sgouros tomfool at as220.org
Mon Nov 27 18:10:45 CET 2006

Philip TAYLOR <P.Taylor at Rhul.Ac.Uk> wrote:

> Surely because \t is recursively defined in terms of itself,
> n'est-ce pas ?

Bien sur.  But there is clearly something stunningly obvious to you that
is not at all clear to me, and a little more detail would be gratefully

o Are you talking about the original definition of \t that is
recursive, or is there something incorrect in my redefinition of \t?

o How would I have known \t was recursively defined?

o Why is \t recursively defined?

o In what way does the recursive definition interfere with the \let?

o How can I predict similar problems?

If, perhaps, you can point me or the original poster to adequate
documentation of whatever features are creating this situation, that
would be fine.  As it is, your answer leaves the situation even more
opaque to me now.

Many thanks,

-tom

> --------
> tom sgouros wrote:
>
> > Perhaps this will make it clearer:
> > \documentclass{article}
> > \begin{document}
> > \t bb
> > \let\tie\t
> > \def\t{t}
> > \let\mycedilla\c
> > \def\c{c}
> > \t bb
> > \tie bb
> > \c b
> > \mycedilla b
> > \end{document}
> > Please explain why the "\t bb" at the beginning of the file behaves
> > differently from the "\tie bb" further down.  When I try this, the first
> > "\t bb" makes a tie over the "bb", but the "\tie bb" produces what
> > appears to be an italic "t" followed by a "bb".  My understanding of the
> > \let would imply to me that the \tie should be identical to the original
> > definition of the \t, but it is not.  Why not?
> >  -tom
> >

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