[Tex/LaTex] Real and Imaginary Parts


There are multiple questions on this site about redefining the real and imaginary part operators. Mine is a bit pedantic. I am quite used to the standard symbols embedded into LaTeX. However for my students, I think it would be clearer to have the second letter appear also, i.e., to have literally Re and Im.

The only problem I have is that I'm very fond of the Fraktur used for the in-build commands, and less so of the ones provided by \mathfrak:

enter image description here

Can I get a Re and Im in the same font as the \Re and \Im commands?

Best Answer

The font used by the \mathfrak command can be changed. An easy way to do that is to use the mathalpha package. For example, here's a comparison of the letters "Re" and "Im" in Esstix fraktur with the usual \Re and \Im symbols.

    \verb|\Re|           & \(\Re\)           \\
    \verb|\mathfrak{Re}| & \(\mathfrak{Re}\) \\
    \verb|\Im|           & \(\Im\)           \\
    \verb|\mathfrak{Im}| & \(\mathfrak{Im}\)

The symbols do not match perfectly, but certainly better than in your original example. In the documentation of the mathalpha package, many fonts are listed, maybe you will find another font you prefer. I think the Mathpi fraktur font might give the same symbols than \Re and \Im, but this font is not free.