How can I get the regular \mathbb and the kpfonts' \mathfrak using fourier?

Question

I need to get the regular \mathbb style (the resulting one only using \amsfonts) and the kpfonts' \mathfrak style using the package fourier.

Thanks.

Answer 1

You can; whether you should is a matter of opinion.

\documentclass{article}
\usepackage{fourier}

\DeclareSymbolFont{AMSb}{U}{msb}{m}{n}
\makeatletter
\DeclareSymbolFontAlphabet{\math@bb}{AMSb}
% see http://tex.stackexchange.com/a/254979/
\AtBeginDocument{\protected\def\mathbb{\math@bb}} 
\makeatother
\DeclareMathAlphabet{\mathfrak}{U}{jkpmia}{m}{it}
\SetMathAlphabet{\mathfrak}{bold}{U}{jkpmia}{bx}{it}

\begin{document}

$A+\mathbb{A}+\mathfrak{A}$

\end{document}

Answer 2

You shouldn't and I wouldn't, but technically you could.

\usepackage{amssymb}
\usepackage{fourier}
\DeclareSymbolFontAlphabet{\math@bb}{AMSb}

This is entirely untested since you didn't provide a minimal working example - or, indeed, any code at all - to work from. So you must be happy adapting it to your local requirements.