I am using the package MinionPro. But I need some symbols, for example, \gnapprox and \mho, available on the package amssymb.
Well, here is my code (as minimal as possible):
\documentclass{report}
\usepackage{MinionPro}
\usepackage{amssymb}
\begin{document}
\[\gnapprox \]
\[\mho \]
\end{document}
But I got the errors:
Command `\mathfrak' already defined. \DeclareMathAlphabet{\mathfrak}{U}{euf}{m}{n}
Command `\mathfrak' not defined as a math alphabet. ...athAlphabet{\mathfrak}{bold}{U}{euf}{b}{n}
Command `\centerdot' already defined. ...ymbol{\centerdot} {\mathbin}{AMSa}{"05}
Command `\veebar' already defined. ...mbol{\veebar} {\mathbin}{AMSa}{"59}
Command `\barwedge' already defined. ...mbol{\barwedge} {\mathbin}{AMSa}{"5A}
Command `\doublebarwedge' already defined. ...ol{\doublebarwedge} {\mathbin}{AMSa}{"5B}
Command `\circledS' already defined. ...mbol{\circledS} {\mathord}{AMSa}{"73}
Command `\dotplus' already defined. ...mbol{\dotplus} {\mathbin}{AMSa}{"75}
Command `\complement' already defined. ...mbol{\complement} {\mathord}{AMSa}{"7B}
Command `\divideontimes' already defined. ...ol{\divideontimes} {\mathbin}{AMSb}{"3E}
Command `\thicksim' already defined. ...ol{\thicksim} {\mathrel}{AMSb}{"73}
Command `\thickapprox' already defined. ...ol{\thickapprox} {\mathrel}{AMSb}{"74}
Command `\hslash' already defined. ...ol{\hslash} {\mathord}{AMSb}{"7D}
How is the right way to use both packages?

\gnapproxand\mhoare in themsbm10font. you cantexdoc amsfontsand look in appendix e (p.37) for their location in the font, or set your own font chart using the technique in the answer already mentioned. – barbara beeton Jan 23 '13 at 16:24\hyphenchar\font45. Should I change something? Should I look at the font table to some particular glyph? – Sigur Jan 23 '13 at 16:38\hyphenchar\font45and leave an empty group{}in its place.\hyphencharis really needed only for text fonts. the relevant command formsbmis in the fileumsb.fd:\DeclareFontFamily{U}{msb}{}– barbara beeton Jan 23 '13 at 16:56\approxfor example. Probably I'm missing something related to the font sizes. – Sigur Jan 23 '13 at 16:59msbm10you might trymsbm9, making a wild guess that minion symbols really are generally smaller than computer modern (which is whatmsbmis based on). – barbara beeton Jan 23 '13 at 17:10MnSymbol, desgined to work with Minion, has some of the symbols, e.g.,\gnapprox. However, it seems that there is no\mho. – mafp Jan 23 '13 at 17:55