(Edited after some comments)
I think this is y most difficult question, so I apologize in advance if I do not explain myself well or is a very strange question.
I would like to get an old-fashion text and I'm thinking use mathspec and fontspec packages for that. For example here is a question about get bourbaki's style book. But the mos detailed answer uses MinionPro package and I haven't lincese. Also here is an answer to change the body font (although the used font isn't free).
For my pourpose I have decided use fontspec' andmathspec. But I don't know how they works. So, can anybody help me with that?
Mymwe` (it doesn't work and I don't know why) is:
\documentclass[a4paper,12pt]{article}
%Basics
\usepackage[T1]{fontenc}
\usepackage{lipsum}
\pagestyle{empty}
%Math
%\usepackage{amsfonts,amssymb}
\usepackage{amsmath}
%Theorems
\usepackage{amsthm}
\usepackage{thmtools}
\newtheoremstyle{theorem}% name of the style to be used
{\topsep}% measure of space to leave above the theorem. E.g.: 3pt
{\topsep}% measure of space to leave below the theorem. E.g.: 3pt
{\itshape}% name of font to use in the body of the theorem
{0pt}% measure of space to indent
{\scshape}% name of head font
{.~---}% punctuation between head and body
{ }% space after theorem head; " " = normal interword space
{\thmname{#1}\thmnumber{ #2}\thmnote{ (#3)}}
\declaretheorem[style=theorem,name=numberwithin=section]{theorem}
%fontspec and mathspec packages
\usepackage{fontspec}
\usepackage{mathspec}
\begin{document}
\lipsum[1] $\sqrt{-g}$.
\begin{equation}
G_{im} = 0
\end{equation}
\lipsum[2]
\[
\Gamma_{ab}^c = \Gamma_{\mu\nu}^\rho .
\]
\begin{theorem}
\lipsum[3]:
\[
\sum_{i=1}^n = \frac{n(n+1)}{2}.
\]
\end{theorem}
\lipsum[4]
\[
\alpha\beta\gamma\delta\kappa \pi\omega\dots
\]
\end{document}
There are other related questions to the old-style apparence, such as this.
Thank you so much.
PD: Use kpfonts for my pourpose is suggested in some of these questions. Anyway, I don't know use any of these packages so... Ifi you think kpfonts is beter for my actual pourpose please feel yourself free to answer my question ''How do I use it?'' by the moment) with kpfonts instead of the others.
fontspec. (Er ... mostly.) For mathematics, you need specialised fonts: either fonts which MATH table support or fonts for traditional maths typesetting. I strongly recommend starting with the LaTeX Font Catalogue unless you have a suitable MATH-table-supporting font available. – cfr Nov 12 '17 at 00:15fontspecandmathspeccommands. When I saidtemplateI mean these commands with an explanation to be able to change the options in the future. – Dog_69 Nov 12 '17 at 12:08kpfontspackage just so you feel free answering with the package that is easiest for you. It was not my intention ask two questions. For themweI'll give one in a couple of minutes. – Dog_69 Nov 12 '17 at 12:16fontspecandmathspec? The question has nothing to do with old fonts, margins, layout etc. All this is just clutter in the question that makes people misunderstand. – Johannes_B Nov 12 '17 at 12:17fontspecandmathspectags at the bottom of your question, you will find plenty of examples. Or you couldtexdoc <package>to see the packages' documentation, of course. How to usefontspecis rather a large question and the answer depends on a whole range of factors. How to usemathspecis a little more contained, but how to work around its bugs and limitations rather less so. Almost certainly you should start by removingfontenc. – cfr Nov 12 '17 at 23:50