Csdrhrt

I prefer to use bm package to bold math. However, I noticed that when used with eulervm, this gives inconsistent results for ‘<’ and ‘>’ characters.

I wonder what causes it and can the usage bm be fixed to get proper ‘<’.

documentclass{article}



usepackage[utf8]{inputenc}

usepackage[T1]{fontenc}



%usepackage{amsmath}



usepackage[euler-digits,euler-hat-accent]{eulervm}



usepackage{bm}



begin{document}



    texttt{hphantom{mathbold}llap{bm}}: quad $ 1 + 1 < 3; quad bm{1 + 1 < 3} $



    texttt{mathbold}: quad $ 1 + 1 < 3; quad mathbold{1 + 1 < 3} $



end{document}

There is an inconsistency in the shape of < and > in the zeurm10 and zeurb10 fonts used for the symbols with eulervm active:

documentclass{article}



usepackage{amsmath}

usepackage[euler-digits,euler-hat-accent]{eulervm}

usepackage{bm}



begin{document}



begin{tabular}{@{}ll@{}}

bm: & $1 + 1 < 3$; $bm{1 + 1 < 3}$ \

mathbold: & $1 + 1 < 3$; $mathbold{1 + 1 < 3}$

end{tabular}



{usefont{U}{zeur}{m}{n}symbol{"3C}}



{usefont{U}{zeur}{b}{n}symbol{"3C}}



end{document}

With mathbold, which is a math alphabet selection, only letters and numbers become bold, but not other symbols.

You can work around the inconsistency by using Computer Modern for the < and > symbols.

documentclass{article}



usepackage{amsmath}

usepackage[euler-digits,euler-hat-accent]{eulervm}

usepackage{bm}



DeclareSymbolFont{cmletters}{OML}{cmm}{m}{it}

SetSymbolFont{cmletters}{bold}{OML}{cmm}{b}{it}

DeclareMathSymbol{<}{mathrel}{cmletters}{"3C}

DeclareMathSymbol{>}{mathrel}{cmletters}{"3E}



begin{document}



begin{tabular}{@{}ll@{}}

bm: & $1 + 1 < 3$; $bm{1 + 1 < 3}$ \

mathbold: & $1 + 1 < 3$; $mathbold{1 + 1 < 3}$

end{tabular}



end{document}

mathbold is math alphabet command (like mathbf, mathit etc) so it has no effect on < . bm though does affect < and you get the character that the package sets up for boldmath, If you add

boldmath



 $ 1 + 1 < 3showlists$

You will see that bm is selecting (in normal math) the fonts used in boldname.

In this case that is

....U/zeur/b/n/10 <

But as you show the bold font's < is a rather different shape to the medium weight font

So this appears to be a font issue.