University of Calgary

# Strict Conditional in LaTeX

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Submitted by Richard Zach on Wed, 02/14/2007 - 2:42am

I just had occasion to have to typeset Lewis's strict conditional symbol in LaTeX. It turns out it isn't in the standard AMS fonts. Peter Smith's LaTeX for Logicians to the rescue! There I found:

1. that the strict conditional symbol is in the fonts that are part of the txfonts and pxfonts packages, and
2. that there is a wonderful 110 page/3 MB comprehensive listing of all LaTeX symbols (by Scott Pakin).

Now it turns out that the point of txfonts and pxfonts is to give you output in Times Roman and Palatino fonts, respectively, with matching math and symbol fonts. That's useful in itself--but if you happen to not want your document to be in Times or Palatino, you can still get \strictif by putting this in the preamble:

\DeclareSymbolFont{symbolsC}{U}{txsyc}{m}{n}
\DeclareMathSymbol{\strictif}{\mathrel}{symbolsC}{74}

Good to know!

That's helpful! Is there a similar trick for typesetting the box arrow' symbol that is sometimes used for the counterfactual conditional? I think it's called \boxright' in pxfonts/txfonts.

Just look up the font and symbol declarations in txfonts.sty:\DeclareMathSymbol{\boxright}{\mathrel}{symbolsC}{128}

I've added (with acknowledgement!) your code for using symbols extracted from txfonts to LaTeX for Logicians. Thanks for that!

ahuenno!

Great! Any thoughts on how to do this for use with XeLaTeX instead? Thanks!