# Doublestroke

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## Using the doublestroke font

Computer Modern and Latin Modern use the msbm font family for blackboard bold. msbm look very dull and usually black board bold should be avoided in math. However, there are certain cases where one needs something *fancier* than math bold. The doublestroke fonts offer one such alternative. For an example of what it looks like, see its documentation.

This is how they can be used with ConTeXt. Note that since we are using doublestroke fonts as the blackboard font, there is really no need to use the blackboard fonts separately; so, the math typescript is overwritten.

\loadmapfile[dstroke.map] \starttypescript [math] [modern,computer-modern,latin-modern,ams] [size] \definebodyfont [17.3pt,14.4pt,12pt][mm] [mc=dsrom12 sa 1] \definebodyfont [11pt,10pt,9pt] [mm] [mc=dsrom10 sa 1] \definebodyfont [8pt,7pt,6pt,5pt,4pt] [mm] [mc=dsrom8 sa 1] \stoptypescript \definetypeface [modern] [mm] [math] [modern] [ams] [encoding=texnansi] \setupbodyfont[reset,modern,10pt] \definefamilysynonym [default] [doublestroke] [mc] \def\dstroke {\fam\purefamily {doublestroke}} \def\doublestroke#1{{\dstroke#1}} The expectation of a random variable $X$ is given by $\doublestroke{E}\{X\}$. The indicator function is given by \startformula \doublestroke{1}(x=a) = \startcases \NC 1 \NC if $x=a$ \NR \NC 0 \NC if $x \ne a$ \NR \stopcases \stopformula

The ConTeXt Garden does not have dsrom fonts installed, so we cannot see the output here.