# What's more common? Re / Im or Fraktur-R / Fraktur-I for real / imaginary part?

Title says it all. What's more common? Is there one to prefere (maybe due to some norm)?

This:

$\operatorname{\mathfrak{R}} z, \operatorname{\mathfrak{I}} z$

or that:

$\operatorname{Re}z, \operatorname{Im}z$ ?

• It's not "fractal". It's "fraktur". Wikipedia. – kahen Nov 10 '12 at 15:55
• This is an opinion question which is hard to answer. My own sense is that the fraktur notation is a bit older and less common nowadays. – Cheerful Parsnip Nov 10 '12 at 15:58
• Because of Latex I'm actually here. I was wondering if there's a special reason why Latex defaults \Re and \Im to the Fraktur versions. – Foo Bar Nov 10 '12 at 16:05
• I see $\operatorname{Re}z, \operatorname{Im}z$ more often. – Martin Thoma Oct 29 '13 at 13:43
• @GrumpyParsnip It's not an opinion question. Perhaps it's poorly defined what population to consider and how to measure, but after that's it's "just" a matter of measuring the the frequency and tell which is more common. – skyking Sep 25 '15 at 6:46

I lean towards readability and I find $\operatorname{Re}z$ and $\operatorname{Im}z$ unambiguously clear.
• Tastes vary, of course, but not being able to write or even recognize fraktur tends to favor readability. The fact that $\mathfrak{A}$ looks like an $U$, not an $A$, and $\mathfrak{P}$ looks like a $B$, not a $P$, has always slightly annoyed me. – lhf Aug 24 '15 at 11:10
• @lhf I cannot believe your $\mathfrak{A}$ was actually an $A$ because it looks like a $U$, $\mathfrak{U}$ is $U$! – Alec Teal Dec 20 '15 at 19:27