diff --git a/ep2.tex b/ep2.tex
index 4ba9ba0..7be9dd0 100644
--- a/ep2.tex
+++ b/ep2.tex
@@ -21,105 +21,103 @@
 
 \date{\today}
 \title{Mathematics of Programming Languages}
-\setep{02}{What is Mathematics?}
+\setep{02}{Basics of Logic}
 
 \begin{document}
 \maketitle
 
-\begin{frame}{Why did I choose to make this?}{}
+\begin{frame}{Why logic?}{}
   \begin{itemize}
-  \item Originally, I just wanted to start from logic
-  \item I read a tweet which made me think not everyone knows what math really is
-  \item I started to ask around online and even on the street
+  \item Logic serves as the backbone of computer science
+  \item it provides the fundamental principles and tools necessary for understanding,
+    designing, and building complex systems
+  \item It forms the basis of logical reasoning, proofs, problem solving, and program correctness.
+  \end{itemize}
+\end{frame}
+
+
+\begin{frame}{What is logic?}{}
+  \begin{itemize}
+  \item One of the key aspects of Mathematics is unambiguity
+  \item The study of the principles of reasoning
+  \item Logic is tool to remove ambiguity from our arguments and thoughts
+  \item Most of the definitions of formal logic have been developed so that they agree with the
+    natural or intuitive logic used by people.
+  \item The difference between formal logic and intuitive logic exists to avoid ambiguity and obtain consistency.
+  \item To put it simply logic is all about what counts as a good argument. A good argument is a valid argument. One that, preserves truth from premises to conclusion.
+  \end{itemize}
+\end{frame}
+
+\begin{frame}{Arguments}{Propositional logic}
+  \begin{itemize}
+  \item An argument is a sequence of statements aimed at demonstrating the truth of an assertion.
+  \item The assertion at the end of the sequence is called the \textbf{conclusion}.
+  \item The preceding statements are called \textbf{premises}.
+  \item As an example:\\
+    \begin{flalign*}
+      &\text{If} \overbrace{\text{Earth is a planet}}^{\textit{premise}} \text{then} \overbrace{\text{Earth is round}}^{\textit{conclusion}}\\
+      &\text{Earth is a planet}\\
+      \therefore \hspace{0.2em} &\text{Earth is round}.
+    \end{flalign*}
+  \end{itemize}
+\end{frame}
+
+\begin{frame}{Arguments}{Symbolic logic}
+  \begin{itemize}
+  \item In logic, the form of an argument is distinguished from its content.
+  \item Logic, won't help you determine the intrinsic merit of an argument’s content.
+  \item It will help you analyze an argument’s form to determine whether the truth of the conclusion follows \textit{necessarily} from the truth of the premises.
+    \begin{flalign*}
+      &\text{If} \overbrace{\text{Earth is a planet}}^{\textit{p}} \text{then} \overbrace{\text{Earth is round}}^{\textit{q}}\\
+      &\overbrace{\text{Earth is a planet}}^{\textit{p}}\\
+      \therefore \hspace{0.2em} &\overbrace{\text{Earth is round}}^{\textit{q}}.
+    \end{flalign*}
+\item Convension: We will use letters \textit{p}, \textit{q}, and \textit{r} to represent
+component sentences.
+  \end{itemize}
+\end{frame}
+
+
+\begin{frame}{Proposition}{}
+  \begin{itemize}
+  \item In any mathematical theory, new terms are defined by using those that have been
+    previously defined. (E.g. A mathematical system)
+  \item This process has to start somewhere
+    \item In logic, the words \textbf{\textit{sentence}}, \textbf{\textit{true}}, \textbf{\textit{false}} are the initial
+      undefined terms
+  \item A \textbf{proposition} (or \textbf{statement}) is a sentence that is true or false but not both.
+  \item For example:
     \begin{itemize}
-    \item To my surprise, the majority of people got it wrong too
-    \item Even other engineers and scientists
+    \item ``Earth is a planet'' (true)
+    \item ``Earth is flat'' (false)
+    \item $x + 5 > 0$ (Depends on the value of $x$)
+    \item ``How are you?'' (not a proposition)
+
     \end{itemize}
   \end{itemize}
 \end{frame}
 
-\begin{frame}{What was the tweet all about?}{}
-  \begin{figure}
-  \centering
-  \pic{ep2/tweet.png}{0.4}
-  \end{figure}
-
+\begin{frame}{Compound propositions}{}
+\begin{itemize}
+\item We can use \textbf{logical connectives} to connect propositions together to form compound propositions.
+\item For example:
+  \begin{itemize}
+  \item $\overbrace{\text{\say{Earth is a planet}}}^{\textit{p}}$ \textbf{or} $\overbrace{\text{\say{Sun is a planet}}}^{\textit{q}}$
+  \item $\overbrace{\text{\say{Alice is at work}}}^{\textit{p}}$ \textbf{and} $\overbrace{\text{\say{Bob is at work}}}^{\textit{q}}$
+  \item $\overbrace{\text{\say{Earth is \textbf{not} flat}}}^{\textit{p}}$
+  \end{itemize}
+\end{itemize}
 \end{frame}
 
-\begin{frame}{Why do we have to start from here?}{}
+\begin{frame}{More symbols}{}
+  Let's rewrite the propositions from before using symbolic variables:
   \begin{itemize}
-  \item Understanding Mathematics helps us to think better
-  \item To asking the right question
-  \item There's no consensus on the definition of mathematics, but I'll give you mine
-  \item My goal is to get you to think
+  \item $\overbrace{\text{\say{Earth is a planet}}}^{\textit{p}}$ \textbf{or} $\overbrace{\text{\say{Sun is a planet}}}^{\textit{q}}$: ($p \lor q$)
+  \item $\overbrace{\text{\say{Alice is at work}}}^{\textit{p}}$ \textbf{and} $\overbrace{\text{\say{Bob is at work}}}^{\textit{q}}$: ($p \land q$)
+  \item $\overbrace{\text{\say{Earth is \textbf{not} flat}}}^{\textit{p}}$: ($\neg p$)
   \end{itemize}
 
 \end{frame}
-
-\begin{frame}{So, What is mathematics?}{}
-  \begin{itemize}
-  \item ``Mathematics is the language in which God has written the universe''
-  \item To put it simply, Mathematics is a language with a specific set of properties
-  \item Usually, a language enables us to express something
-  \item For example, musical notation is the language to express music
-
-  \end{itemize}
-\end{frame}
-
-\begin{frame}{Language of Music}{}
-  \centering
-  Anyone who speaks the language of musical notations understands this sheet
-  \begin{figure}
-  \centering
-  \pic{ep2/music_score.png}{0.65}
-
-  Maths is the same, I can express my thoughts about something in terms of mathematics
-  \end{figure}
-\end{frame}
-
-\begin{frame}{Maths the Framework}{}
-  \begin{itemize}
-  \item One can produce nonsense in Maths as well
-  \item But maths provides a framework that eliminates nonsense, errors and ambiguity
-  \item Mathematics is a precise language
-  \end{itemize}
-\end{frame}
-
-\begin{frame}{Not just a language}{}
-  \begin{itemize}
-  \item It's not just a language, it's a language + reasoning, it's a tool for reasoning
-  \item It's a big collection of some people's careful thoughts
-  \item In form of provable and precise statements
-  \end{itemize}
-\end{frame}
-
-\begin{frame}{So, What is mathematics?}{}
-  \begin{itemize}
-  \item By Mathematics, it is possible to connect one statement to others.
-  \item Mathematics is a way of going from one set of statements to another via reason.
-  \item It's an interconnected web, how an idea in one field drives you to others
-  \end{itemize}
-
-\end{frame}
-
-
-\begin{frame}{What are those statements all about?}{}
-  \begin{itemize}
-  \item Humans are pattern recognizing machines. (We will talk about it more in the episode)
-  \item Mathematics is all about generalizing those patterns via abstractions
-  \item And study the relations between those abstractions
-  \item Usually, there are more than one way to describe the same thing
-  \item different between doing math and using math
-    \begin{itemize}
-      \item Mathematicians want to make their reasoning as general as possible
-      \item But math users usually want special cases
-    \end{itemize}
-  \end{itemize}
-\end{frame}
-
-\begin{frame}{}
-\end{frame}
-
 \begin{frame}{Contact}{}
   Please, share your thoughts and ideas or researches and papers that you want me to have a look at via:
   \begin{itemize}
diff --git a/ep3.tex b/ep3.tex
new file mode 100644
index 0000000..cc635f1
--- /dev/null
+++ b/ep3.tex
@@ -0,0 +1,10 @@
+\usepackage[sfdefault]{roboto}  %% Option 'sfdefault' only if the base font of the document is to be sans serif
+\usepackage[T1]{fontenc}
+\mdseries
+\documentclass{article}
+\begin{document}
+\begin{math}
+  \psi(x_b, t_b) = \int_{-\infty}^{+\infty} K(b, a)\psi(x_a, t_a)dx_a
+  \end{math}
+%% K(b, a) = (\frac{m}{ih(t_b - t_a)})^\frac{1}{2} exp \frac{im(x_b - x_a)^2}{2\hbar(t_b - t_a)}
+\end{document}
diff --git a/lxpresent.cls b/lxpresent.cls
index 7e050d6..2a294d4 100644
--- a/lxpresent.cls
+++ b/lxpresent.cls
@@ -30,6 +30,8 @@
 \RequirePackage[normalem]{ulem}
 \RequirePackage{amsmath}
 \RequirePackage{amssymb}
+\RequirePackage{mathtools}
+\RequirePackage{dirtytalk}
 \RequirePackage{capt-of}
 
 \newcommand*{\setep}[2]{\def\@ep{#1}\def\@eptitle{#2}}