\newfont{\biv   }{cmbxti10 at  5 truept} % tiny
\newfont{\bivii }{cmbxti10 at  7 truept} % scriptsize
\newfont{\biviii}{cmbxti10 at  8 truept} % footnotesize
\newfont{\biix  }{cmbxti10 at  9 truept} % small
\newfont{\bix   }{cmbxti10 at 10 truept} % normalsize
\newfont{\bixii }{cmbxti10 at 12 truept} % large
\newfont{\bixiv }{cmbxti10 at 14 truept} % Large
\newfont{\bixvii}{cmbxti10 at 17 truept} % LARGE
\newfont{\bixx  }{cmbxti10 at 20 truept} % huge
\newfont{\bixxv }{cmbxti10 at 25 truept} % Huge

\newcommand{\bi}{%
\ifx\@currsize\tiny\biv%
\else\ifx\@currsize\scriptsize\bivii%
\else\ifx\@currsize\footnotesize\biviii%
\else\ifx\@currsize\small\biix%
\else\ifx\@currsize\normalsize\bix%
\else\ifx\@currsize\large\bixii%
\else\ifx\@currsize\Large\bixiv%
\else\ifx\@currsize\LARGE\bixvii%
\else\ifx\@currsize\huge\bixx%
\else\ifx\@currsize\Huge\bixxv%
\else\typeout{bad currsize: \@currsize}
\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi%
}

