[texhax] controlling expansion

Michael Doob mdoob at cc.umanitoba.ca
Thu Feb 28 16:02:39 CET 2013

On 13-02-28 08:51 AM, Neal H. Walfield wrote:
> I spent some time reading and found a good solution for determining
> whether an argument is empty in David Solomon's Advanced TeXbook:
>    \ifx\empty#1\empty empty \else not empty\fi
> Nice trick!  TeX requires a lot of lateral thinking.

Cute, but what about \empty{\empty}? :-)


Michael Doob                    Telephone: (204) 474-9796
Department of Mathematics       Fax: (204) 474-7606
University of Manitoba          email: Michael_Doob at umanitoba.ca
Winnipeg, MB, Canada R3T 2N2

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