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I want to understand the TeX instructions

  \ifx\@tempb`\edef\next##1{%

Especially, I want understand what meaning of ` symbol before \edef.
As I know ifx compare two statements, symbol ` for symbol taking - `\A takes a code of symbol A. Or I am wrong? Thanks.

Mico
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Andrew
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  • I have replaced the ` character with a ' character as there is an interference with TeX.SX formatting and the TeX character. – percusse Feb 21 '12 at 14:29

1 Answers1

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The ` there has no connection to the use of ` to get the character code of a symbol, it should be read as

\ifx\@tempb`
    \edef\next....

that is if the two tokens \@tempb and ` are equal then define \next to be something. They will be equal if for example \@tempb had been defined by

\let\@tempb=`

or (if I recognise that code fragment:-) if it had been defined by \futurelet rather than \let.

Daniel
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David Carlisle
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  • Yes, David, this is fragment from one of yours answers on my question. I want understand those deeper. Thanks for explanation. – Andrew Feb 21 '12 at 14:49