diff --git a/04/Solution #04/Presentation.pdf b/04/Solution #04/Presentation.pdf
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diff --git a/04/Solution #04/Presentation/Presentacion.tex b/04/Solution #04/Presentation/Presentacion.tex
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--- /dev/null
+++ b/04/Solution #04/Presentation/Presentacion.tex	
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+%%Tema para beamer "Imunam", versión 1.0
+
+\documentclass{beamer}
+\usepackage[utf8]{inputenc}
+\usepackage[T1]{fontenc} 
+\usepackage[spanish]{babel} 
+\graphicspath{ {images/} }
+\usepackage{mathtools}
+\usepackage{tikz}
+
+
+%% Logos de restaurantes:
+\newcommand{\logomanekin}{images/logomanekin}
+
+%%Se define el "environment" teorema
+%% The "environment" theorem is defined
+\newtheorem{Formula}{Formula} 
+
+
+%%Tema de beamer "Imunam"
+%% Theme of beamer "Imunam"
+\usetheme[cuernavaca]{Imunam} 
+%\usetheme{Imunam} 
+%%Si se omite "[cuernavaca]" en éste comando, el logotipo se imprime sin la 
+%%leyenda "Unidad Cuernavaca" en la parte inferior.
+%% If "[cuernavaca]" is omitted in this command, the logo is printed without the
+%% legend "Cuernavaca Unit" in the lower part.
+
+\title{Proof of the Pythagoras theorem.}
+\author{Enrique Andrade Gonzalez %Nombre del autor % Author's name
+	      \texttt{e.andrade@udc.es}} %email
+	      
+\date{Computer tools in mathematican's work} %subject
+
+%\institute{Instituto de Matemáticas, unidad Cuernavaca} 
+%%Instituto del ponenete, dado que el texto "Intituto de matemáticas" aparece
+%%en el logo, parece redundante incluirlo además con éste comando.
+
+\begin{document}
+
+\begin{frame}
+
+  \titlepage %Necesario para generar la portada
+  
+\end{frame}
+
+%%La siguiente diapositiva es opcional, si se quiere la tabla de contenidos
+%%Se sebe compilar dos veces el documento para que funcione
+%--------------------------------------------------------------------------
+\begin{frame}
+\tableofcontents %Imprime la tabla de contenido
+\end{frame}
+%--------------------------------------------------------------------------
+
+\section{Introduction} %%Título de la sección (Opcional)
+\begin{frame}
+  \frametitle{Introduction}
+  \framesubtitle{objective} %%Subtítulo de la diapositiva (opcional)
+  In this presentation we try to show a proof of the Pythagorean theorem.
+  There are many demonstrations, but this one is one of the simplest.
+\end{frame}
+
+\section{Proof of the Pythagorean theorem} %%Otra sección
+\begin{frame}
+    \frametitle{Concept}
+    Suppose we have a square of side \textbf{r} and on each of its sides we place a right triangle of legs \textbf{x} and \textbf{y}. As in this situation the hypotenuse of each of the triangles is \textbf{r} we want to prove that:
+    \\\
+    \begin{Formula} %%Uso del "environment" definido al inicio del documento.
+        \[x^{2}+y^{2}=r^{2}\]
+    \end{Formula}
+    
+
+\end{frame}
+
+\begin{frame}
+    \frametitle{The figure}
+    The figure that is obtained is the following:
+    \begin{center}
+    \begin{tikzpicture}[scale=0.8]
+    %\begin{tikzpicture}
+        %\draw (0,0) circle (1cm);    
+        \draw [fill=green] (-2,-2) rectangle (2,2); 
+        \draw [fill=red] (-2,0) -- (0,2) -- (2,0) -- (0,-2) -- cycle;
+        % r
+        \draw [dotted]
+        (0.75,1) node[black] {r}
+        (0.75,-1) node[black] {r}
+        (-0.75,1) node[black] {r}
+        (-0.75,-1) node[black] {r};
+        
+        % x y
+        \draw [dotted]
+        (1,-2.2) node[black] {y}
+        (1,2.2) node[black] {x}
+        (-1,2.2) node[black] {y}
+        (-1,-2.2) node[black] {x}
+        
+        (2.2,1) node[black] {y}
+        (2.2,-1) node[black] {x}
+        (-2.2,1) node[black] {x}
+        (-2.2,-1) node[black] {y};
+        
+    \end{tikzpicture}
+    \[x^{2}+y^{2}=r^{2}\]
+    \end{center}
+\end{frame}
+
+
+%\section{Restaurants} %%Otra sección
+\begin{frame}
+    \frametitle{Conclusions}
+    \begin{itemize}
+        \item Each side of the \textbf{green square} is the sum of \textbf{x} and \textbf{y}. Therefore, the area of the square is: \[(x+y)^{2}\]
+        \item For the same reason, the area of the \textbf{red square} is: \[r^{2}\]
+        \item The area of each of the \textbf{green triangles} (y, x and r) is:\[\frac{x+y}{2}\]
+
+    \end{itemize}
+\end{frame}
+
+
+\section{Demonstration} %%Otra sección
+\begin{frame}
+    \frametitle{Demonstration}
+    
+    \begin{itemize}
+        \item The green square is formed by the red square and the four green triangles, so the sum of all the areas is: \[(x+y)^{2}=r^{2} + 4 (\frac{x+y}{2})\]
+        \item We develop the left part of equality: \[(x+y)^{2}=x^{2} + 2xy + y^{2}\]
+        \item We substitute in the first formula: \[x^{2} + 2xy + y^{2} = r^{2} + 2xy\]
+        \item \textbf{2xy} is eliminated on both sides of the equality, and we obtain the desired result: \[x^{2} + y^{2} = r^{2}\]
+    \end{itemize}
+
+
+\end{frame}
+
+\end{document}
\ No newline at end of file
diff --git a/04/Solution #04/Presentation/beamercolorthemeImunam.sty b/04/Solution #04/Presentation/beamercolorthemeImunam.sty
new file mode 100755
index 0000000..98a53e2
--- /dev/null
+++ b/04/Solution #04/Presentation/beamercolorthemeImunam.sty	
@@ -0,0 +1,14 @@
+\mode<presentation>
+
+\setbeamercolor*{title page header}{fg=white}
+\setbeamercolor*{author}{fg=white}
+\setbeamercolor*{date}{fg=white}
+\setbeamercolor*{institute}{fg=white}
+\setbeamercolor*{sectiontitle}{fg=black}
+
+\setbeamercolor*{item}{fg=azulunam}
+
+\setbeamercolor{block title}{use=structure,fg=white,bg=azulunam}
+
+
+\mode<all>
diff --git a/04/Solution #04/Presentation/beamerinnerthemeImunam.sty b/04/Solution #04/Presentation/beamerinnerthemeImunam.sty
new file mode 100755
index 0000000..63b1575
--- /dev/null
+++ b/04/Solution #04/Presentation/beamerinnerthemeImunam.sty	
@@ -0,0 +1,60 @@
+\mode<presentation>
+
+\setbeamertemplate{background}{
+    \begin{tikzpicture}
+      \useasboundingbox (0,0) rectangle(\the\paperwidth,\the\paperheight);
+      \fill[color=orounam] (0,0) rectangle(\the\paperwidth, \the\paperheight);
+      \fill[color=azulunam] (0,0) rectangle(0.59\paperwidth, \the\paperheight);
+      \fill[color=azulunam] (0.60\paperwidth,0.41\paperheight) rectangle(\the\paperwidth, \the\paperheight);
+      \fill[color=azulunam] (0.77\paperwidth,0) rectangle(\the\paperwidth, 0.40\paperheight);
+      %\useasboundingbox (0.77\paperwidth,0) rectangle(\the\paperwidth, 0.40\paperheight);
+      \fill[color=azulunam] (0.60\paperwidth,0) rectangle(0.76\paperwidth, 0.23\paperheight);
+      \fill[color=azulunam] (0.60\paperwidth, 0.24\paperheight) rectangle(0.69\paperwidth, 0.40\paperheight);
+      \fill[color=azulunam] (0.70\paperwidth, 0.31\paperheight) rectangle(0.76\paperwidth, 0.40\paperheight);
+      \fill[color=azulunam] (0.72\paperwidth, 0.24\paperheight) rectangle(0.76\paperwidth, 0.30\paperheight);
+      \fill[color=azulunam] (0.70\paperwidth, 0.24\paperheight) rectangle(0.71\paperwidth, 0.28\paperheight);
+      \ifnum\thepage>1\relax%
+       \fill[white, opacity=1] (0,0) rectangle(\the\paperwidth, \the\paperheight);
+       \includegraphics[width=\paperwidth, height=0.8\paperheight, angle=75]{images/forma4.jpg}
+      \fi
+    \end{tikzpicture}
+}
+
+\setbeamerfont{date}{size=\small, shape=\upshape}
+\setbeamerfont{title}{size=\huge, shape=\scshape}
+\setbeamerfont{institute}{size=\tiny, shape=\itshape}
+
+
+\defbeamertemplate*{title page}{Imunam}[1][]
+{
+  \begin{textblock}{9}(0.2,2.5)
+    \begin{beamercolorbox}[center,sep=1pt,#1]{title page header}
+      \usebeamerfont{title}\inserttitle\par%
+    \end{beamercolorbox}
+  \end{textblock}
+  \vskip4.5cm%
+  \begin{beamercolorbox}[wd=6cm,leftskip=0cm,#1]{author}
+    \usebeamerfont{date}\insertauthor%
+  \end{beamercolorbox}
+  \vskip0.1cm%
+  \begin{beamercolorbox}[wd=6cm, #1]{institute}
+    \usebeamerfont{institute}\insertinstitute
+  \end{beamercolorbox}
+
+  
+  \begin{textblock}{5.6}(9.7,5)
+    \begin{beamercolorbox}[right]{date}
+	\usebeamerfont{date}\insertdate%
+    \end{beamercolorbox}
+  \end{textblock}
+  
+  \begin{textblock}{4}(12.9,11.8)
+    \includegraphics[width=2cm]{\logoblanco}
+  \end{textblock}
+  \vfill
+}
+
+\setbeamertemplate{items}[triangle]
+\setbeamertemplate{sections/subsections in toc}[square]
+
+\mode<all>
\ No newline at end of file
diff --git a/04/Solution #04/Presentation/beamerouterthemeImunam.sty b/04/Solution #04/Presentation/beamerouterthemeImunam.sty
new file mode 100755
index 0000000..81172c3
--- /dev/null
+++ b/04/Solution #04/Presentation/beamerouterthemeImunam.sty	
@@ -0,0 +1,39 @@
+\mode<presentation>
+
+\setbeamerfont{sectiontitle}{size=\huge, shape=\scshape}
+
+%Barra de título
+\defbeamertemplate*{frametitle}{Imunam}[1][]
+{
+  \vskip0.2cm
+  \begin{beamercolorbox}[right]{sectiontitle}
+	\usebeamerfont{date}\insertsection
+  \end{beamercolorbox}
+  \vskip-0.2cm
+    \definecolor{imred}{HTML}{BD2026}
+    \definecolor{imyellow}{HTML}{FCED27}
+    \definecolor{imorange}{HTML}{F6B419}
+  \begin{beamercolorbox}[wd=\paperwidth,ht=1.9cm]{frametitle}
+    \begin{tikzpicture}
+      \useasboundingbox (0,0) rectangle(\the\paperwidth,1.4);
+      {\node[anchor=west, white] at (0.4, 0.8){\includegraphics[width=1.5cm]{\logoimate}};}
+      \fill[azulunam](2.45, 0.3) rectangle(\paperwidth,1.4);
+      \ifx\insertframesubtitle\@empty%
+       {\node[anchor=west, white, font=\large] at (3.0,0.82){\insertframetitle};}
+       \else%
+       {\node[anchor=west, white, font=\large] at (3.0, 1.02){\insertframetitle};%
+       \node[anchor=west, white, font=\small] at (3.0, 0.63){\insertframesubtitle};}%
+       \fi
+     \end{tikzpicture}
+   \end{beamercolorbox}
+   \vskip-0.5cm
+}
+
+%%Impide que se imprima el logo
+\defbeamertemplate*{sidebar right}{sidebar theme}
+{%
+    \vfill%
+    \llap{\usebeamertemplate***{navigation symbols}\hskip0.1cm}%
+    \vskip2pt}
+
+\mode<all>
diff --git a/04/Solution #04/Presentation/beamerthemeImunam.sty b/04/Solution #04/Presentation/beamerthemeImunam.sty
new file mode 100755
index 0000000..f895a85
--- /dev/null
+++ b/04/Solution #04/Presentation/beamerthemeImunam.sty	
@@ -0,0 +1,36 @@
+\mode<presentation>
+
+%Paquete requerido
+\RequirePackage{tikz}
+\RequirePackage{graphicx}
+\RequirePackage{amssymb}
+\RequirePackage{xcolor}
+
+\RequirePackage[absolute, overlay]{textpos}
+\definecolor{orounam}{HTML}{CC9933}
+\definecolor{azulunam}{HTML}{13406F}
+
+\newcommand{\logoimate}{images/IM_logo.pdf}
+\newcommand{\logoblanco}{images/IM_blanco.pdf}
+
+\DeclareOption{cuernavaca}{
+    \renewcommand{\logoimate}{images/IM_Cuerna.pdf}
+    \renewcommand{\logoblanco}{images/logo.pdf}
+}
+\ProcessOptions\relax
+
+%Configuraciones
+\usecolortheme{Imunam}
+\useinnertheme{Imunam}
+\useoutertheme{Imunam}
+
+
+\setbeamertemplate{navigation symbols}{}
+\setbeamertemplate{blocks}[rounded][shadow=true]
+
+%\DeclareOption{cuernavaca}{
+%    \renewcommand{\logoimate}{IM_Cuerna.pdf}
+%    \renewcommand{\logoblanco}{IM_Cuerna_blanco.pdf}
+%}
+
+\mode<all>
diff --git a/04/Solution #04/Presentation/images/IM_Cuerna.pdf b/04/Solution #04/Presentation/images/IM_Cuerna.pdf
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diff --git a/04/Solution #04/Presentation/images/IM_Cuerna.tex b/04/Solution #04/Presentation/images/IM_Cuerna.tex
new file mode 100755
index 0000000..c1987a1
--- /dev/null
+++ b/04/Solution #04/Presentation/images/IM_Cuerna.tex	
@@ -0,0 +1,20 @@
+\documentclass[tikz]{standalone}
+\usepackage{tikz}
+\usepackage{tgadventor}
+
+\begin{document}
+
+\definecolor{imred}{HTML}{BD2026}
+\definecolor{imyellow}{HTML}{FCED27}
+\definecolor{imorange}{HTML}{F6B419}
+\begin{tikzpicture}[scale=0.3, line width=2pt]
+    \draw[black, fill=imred] (16.6,8.88) -- (21.84,13.28) -- (13,19.6) -- (10.96,13.12);
+    \draw[black, fill=imorange] (4,13.16) -- (7.68,2.27) -- (9.77, 8.84) -- cycle;
+    \draw[black, fill=imyellow] (4,13.16) -- (15.22, 13.04) -- (13.04,6.44) -- cycle;
+    \draw[black, fill=imorange] (7.68,2.16) -- (13.04,6.44) -- (9.77, 8.84) -- cycle;
+    \draw[black, fill=white] (15.18,12.80) -- (13.83,8.76) -- (16.6, 8.88) -- cycle;
+    \node[minimum size=8em, align=left] (title) at (25.8, 5) {\textsf{\Huge Instituto de} \\
+        \textsf{\Huge Matem\'aticas} \vspace{2mm}\\
+        \textsf{\fontsize{16pt}{1em}\selectfont Unidad Cuernavaca}};
+\end{tikzpicture}
+\end{document}
\ No newline at end of file
diff --git a/04/Solution #04/Presentation/images/IM_Cuerna_blanco.tex b/04/Solution #04/Presentation/images/IM_Cuerna_blanco.tex
new file mode 100755
index 0000000..6d2bca2
--- /dev/null
+++ b/04/Solution #04/Presentation/images/IM_Cuerna_blanco.tex	
@@ -0,0 +1,19 @@
+\documentclass[tikz]{standalone}
+\usepackage{tikz}
+\usepackage{tgadventor}
+
+\begin{document}
+\definecolor{azulunam}{HTML}{13406F}
+\begin{tikzpicture}[scale=0.3, line width=2pt, color=white]
+    \draw[azulunam, fill=white] (16.6,8.88) -- (21.84,13.28) -- (13,19.6) -- (10.96,13.12);
+    \draw[azulunam, fill=white] (4,13.16) -- (7.68,2.27) -- (9.77, 8.84) -- cycle;
+    \draw[azulunam, fill=white] (4,13.16) -- (15.22, 13.04) -- (13.04,6.44) -- cycle;
+    \draw[azulunam, fill=white] (7.68,2.16) -- (13.04,6.44) -- (9.77, 8.84) -- cycle;
+    \draw[azulunam, fill=white] (15.18,12.80) -- (13.83,8.76) -- (16.6, 8.88) -- cycle;
+    \node[minimum size=8em, align=left] (title) at (25.8, 5) {\textsf{\Huge Instituto de} \\
+        \textsf{\Huge Matem\'aticas} \vspace{2mm}\\
+        \textsf{\fontsize{16pt}{1em}\selectfont Unidad Cuernavaca}};
+\end{tikzpicture}
+\end{document}
+
+\end{document}
\ No newline at end of file
diff --git a/04/Solution #04/Presentation/images/IM_blanco.tex b/04/Solution #04/Presentation/images/IM_blanco.tex
new file mode 100755
index 0000000..2183cd9
--- /dev/null
+++ b/04/Solution #04/Presentation/images/IM_blanco.tex	
@@ -0,0 +1,17 @@
+\documentclass[tikz]{standalone}
+\usepackage{tikz}
+\usepackage{tgadventor}
+
+\begin{document}
+\definecolor{azulunam}{HTML}{13406F}
+\begin{tikzpicture}[scale=0.3, line width=2pt, color=white]
+    \draw[azulunam, fill=white] (16.6,8.88) -- (21.84,13.28) -- (13,19.6) -- (10.96,13.12);
+    \draw[azulunam, fill=white] (4,13.16) -- (7.68,2.27) -- (9.77, 8.84) -- cycle;
+    \draw[azulunam, fill=white] (4,13.16) -- (15.22, 13.04) -- (13.04,6.44) -- cycle;
+    \draw[azulunam, fill=white] (7.68,2.16) -- (13.04,6.44) -- (9.77, 8.84) -- cycle;
+    \draw[azulunam, fill=white] (15.18,12.80) -- (13.83,8.76) -- (16.6, 8.88) -- cycle;
+    \node[minimum size=8em, align=left] (title) at (25.8, 5) {\textsf{\Huge Faculty of Mathematics and Computer Science} \\ \\ \textsf{\Huge Matem\'aticas}};
+\end{tikzpicture}
+\end{document}
+
+\end{document}
\ No newline at end of file
diff --git a/04/Solution #04/Presentation/images/forma4.jpg b/04/Solution #04/Presentation/images/forma4.jpg
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diff --git a/04/Solution #04/Presentation/images/logo.pdf b/04/Solution #04/Presentation/images/logo.pdf
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