# How to make Greek letters in formulas in direct font in LaTeX

As you know, in the LaTeX formulas, Greek letters and integrals are oblique. In the old Soviet literature in formulas, Greek letters and integrals were direct and some people require that in letters, dissertations, abstracts and other documents, Greek letters should also be in direct font.
The following is a package that can implement this in LaTeX. I made this package in the process of working on my dissertation, when they asked me that the Greek letters in the formulas should be in direct font.

This is a picture that shows how formulas written in LaTeX will look like if you connect my package:

If someone suddenly needed this, then see Cat.

I did not find a finished package for LaTeX that implements such a function. The search for a solution led to the use of the mathptm package, but with this package the formulas begin to look like in Word'e. Latin characters become intermediate between normal and bold. Also, the bold style of the \ section, \ subsection headers is lost.

In general, I had to make my own bike.
The idea underlying my package is borrowed here . The link describes how to redefine Greek letters in the preamble of the document.

Everything is designed in the form of three packages:

• rumathgrk - defines direct Greek characters
for example \ alphaup - direct letter "alpha" \ betaup - direct letter "beta", etc.
• rumathgrk1 - Overrides standard Greek characters (\ alpha, \ beta, etc.) so that they are straight
• fixint - redefines integrals to be straight. It should be noted that the disser class with the fixint option does the same.

For use, connect any of these packages in any combination in the preamble. To use the fixint package, you need to connect the amsmath package. The packages are compatible with the popular disser dissertation style sheet.

Here is an example of a minimal document:

\documentclass[a4paper,12pt]{article}
\usepackage[koi8-r]{inputenc}
\usepackage[russian]{babel}
\usepackage{hyperref}
\usepackage{mathtext}
\usepackage{amsmath}
\usepackage{fixint}  % здесь подключили наши пакеты
\usepackage{rumathgrk1} % теперь греческие буквы и интегралы будут переопределены
\begin{document}
% В этих формулах греческие буквы печатаются прямым шрифтом
$$S(\omega)=F[s(t)]=\int\limits_{-\infty}^{+\infty}s(t)\mbox{e} ^{-j\omega t} dt$$
$$F=\frac{q_1 q_2}{4\pi \varepsilon_0 \varepsilon r^2}$$
\end{document}


If direct integrals and Greek letters in the document are no longer needed, then you just need to remove the rumathgrk1 and fixint packages from the preamble.

You can collect ready-made packages from Githba: from here On Linux, if git is installed, this can be done with the command:
git clone https://github.com/ra3xdh/rumathgrk


To install on Linux and TeXlive in the console, go to the directory with the package and run the command:

make install


Windows packages have not been tested, but should work too. You need to install them for MiKTeX manually. Use for any purpose is allowed.

In conclusion, I note that I prefer the standard inclined Greek letters and integrals from LaTeX. I also note that, in general, our people are tolerant of inclined integrals and Greek letters. Usually the standard LaTeX font suits everyone.