# \mathrm{\Delta} in slant in the equation environment

I tried to write an equation, including \Delta. But it also shows in slant, even though I tried \mathrm{} or \text{}. CUEDthesisPSnPDF template and two math packages are used

\usepackage{amssymb}
\usepackage{amsmath}

$$\Delta E \Delta{t} \approx \frac{h}{2 \pi}\\ \mathrm{\Delta} E \, \text{\Delta} t \label{fun:naturalline}$$


It seems \mathrm does not work here. How can I solve this problem? Thank you in advance.

• Welcome to TeX.SX. You can have a look at package upgreek. – Johannes_B Feb 2 at 7:24
• What would make the Delta less slanted? en.wikipedia.org/wiki/Delta_(letter) – Johannes_B Feb 2 at 7:27
• Where did you obtain CUEDthesisPSnPDF? I'm almost certain that the class file sets the greek symbols to italic, but we can't say without all information. – Henri Menke Feb 2 at 7:30
• I did an online search for the template and chose the first result github.com/kks32/phd-thesis-template. Then I cannot reproduce: screenshot. Please provide a minimal working example (MWE). – Henri Menke Feb 2 at 7:45
• The LaTeX kernel sets things up in such a way that \Delta yields an upright (uppercase) delta; the amsmath package offers, in addition, \varDelta for an italic (slanted) uppercase delta (and similarly for other uppercase greek letters). See @HenriMenke’s comment. – GuM Feb 2 at 10:58

You could load the upgreek package and write \Updelta to generate an 'upright' uppercase-Delta character.

\documentclass{article}
\usepackage{upgreek}
\begin{document}
$\delta$ $\updelta$

$\Delta$ $\Updelta$ % note: \Updelta, not \upDelta
\end{document}


TL;dr: Several packages define \increment or \upDelta.

If you can use unicode-math, there are a number of different variants of this symbol, and a number of different ways to get it:

\documentclass[varwidth = 10cm, preview]{standalone}
\usepackage[svgnames, Svgnames]{xcolor}
\usepackage[math-style=literal]{unicode-math}

\defaultfontfeatures{ Scale = MatchUppercase }
% Make it blatant which font is being used:
\setmainfont{Latin Modern Roman}[Scale = 1.0, Color = Crimson]
\setmonofont{Latin Modern Mono}[Color = DarkGray]
\setmathfont{Latin Modern Math}[Color = Orange]
\setmathfont[range=up]{Latin Modern Math}[Color = SkyBlue]
\setmathfont[range=bfsfup]{Latin Modern Sans}[Color = Indigo]
\setmathrm{Latin Modern Roman}[Color = LimeGreen]

\begin{document}
\begin{itemize}
\item \texttt{\textbackslash{}increment} $$\increment$$
\item \texttt{Δ} $$Δ$$
\item \texttt{\textbackslash{}upDelta} $$\upDelta$$
\item \texttt{\textbackslash{}mupDelta} $$\mupDelta$$
\item \texttt{\textbackslash{}symup\{\textbackslash{}Delta\}} $$\symup{\Delta}$$
\item \texttt{\textbackslash{}mathrm\{\textbackslash{}mupDelta\}} $$\mathrm{\mupDelta}$$
\item \texttt{\textbackslash{}mathup\{\textbackslash{}mupDelta\}} $$\mathup{\mupDelta}$$
\item \texttt{\textbackslash{}mbox\{\textbackslash{}mupDelta\}} $$\mbox{\mupDelta}$$
\item \texttt{\textbackslash{}mbox\{Δ\}} $$\mbox{Δ}$$
\item \texttt{\textbackslash{}mbfsansDelta} $$\mbfsansDelta$$
\item \texttt{\textbackslash{}symbfsfup\{\textbackslash{}Delta\}} $$\symbfsfup{\Delta}$$
\end{itemize}
\end{document}


And at least three more, but you get the idea. Of these, \increment is the math operator ∆ (U+2206) and the others are the Greek letter Δ (U+0394).

If you need backward compatibility with PDFTeX, one way to get it is to load an upright Greek alphabet with isomath. Another is to load an upright font with Greek letters as a math alphabet (such as AMS Euler, zeur) and define either \increment or \upDelta with \DeclareMathSymbol.

Several legacy packages define this symbol in different ways, including:

• upgreek: \upDelta
• stix, stix2: \increment
• kpfonts: \Deltaup
• fourier: \otherDelta