[Tex/LaTex] Where is amsfont.sty and how to install it for MiKTeX?

fontsinstallingmiktex

I am trying to use \mathbb. It seems that this command requires \usepackage{amsfont}. But as soon as I use this package, my MikTeX 2.9 installation complains that it doesn't find amsfont.sty. So where is it and how do I install it?

Here's the "formula" that I try to process:

\documentclass{article}
\usepackage{amstext} 
\usepackage{amsmath} 
\usepackage{amsfont} 
    \pagestyle{empty}

    \begin{document}
     $   \mathbb{R}^n   $
    \end{document}

I should also note that there is a file with the name amsfonts.sty under MiKTeX-2.9\tex\latex\amsfonts (note the plural, amsfonts.sty vs amsfont.sty).

The complete error message is:

This is pdfTeX, Version 3.1415926-2.3-1.40.12 (MiKTeX 2.9)
entering extended mode
(c:/temp/formula.tex
LaTeX2e <2011/06/27>
Babel <v3.8m> and hyphenation patterns for english, afrikaans, ancientgreek, ar
abic, armenian, assamese, basque, bengali, bokmal, bulgarian, catalan, coptic,
croatian, czech, danish, dutch, esperanto, estonian, farsi, finnish, french, ga
lician, german, german-x-2009-06-19, greek, gujarati, hindi, hungarian, iceland
ic, indonesian, interlingua, irish, italian, kannada, kurmanji, lao, latin, lat
vian, lithuanian, malayalam, marathi, mongolian, mongolianlmc, monogreek, ngerm
an, ngerman-x-2009-06-19, nynorsk, oriya, panjabi, pinyin, polish, portuguese,
romanian, russian, sanskrit, serbian, slovak, slovenian, spanish, swedish, swis
sgerman, tamil, telugu, turkish, turkmen, ukenglish, ukrainian, uppersorbian, u
senglishmax, welsh, loaded.
(C:\tools\MiKTeX-2.9\tex\latex\base\article.cls
Document Class: article 2007/10/19 v1.4h Standard LaTeX document class
(C:\tools\MiKTeX-2.9\tex\latex\base\size10.clo))
(C:\tools\MiKTeX-2.9\tex\latex\ams\math\amstext.sty
(C:\tools\MiKTeX-2.9\tex\latex\ams\math\amsgen.sty))
(C:\tools\MiKTeX-2.9\tex\latex\ams\math\amsmath.sty
For additional information on amsmath, use the `?' option.
(C:\tools\MiKTeX-2.9\tex\latex\ams\math\amsbsy.sty)
(C:\tools\MiKTeX-2.9\tex\latex\ams\math\amsopn.sty))

Best Answer

Try amsfonts, with an s at the end.