Remove stray "introduction" section.

doc/modular_congruence_multiplication_proof.pdf

diff --git a/doc/modular_congruence_multiplication_proof.pdf b/doc/modular_congruence_multiplication_proof.pdf
index 607f668..83c6dc1 100644
--- a/doc/modular_congruence_multiplication_proof.pdf
+++ b/doc/modular_congruence_multiplication_proof.pdf
Binary files differ

doc/modular_congruence_multiplication_proof.tex

diff --git a/doc/modular_congruence_multiplication_proof.tex b/doc/modular_congruence_multiplication_proof.tex
index 10e9f31..95a45d6 100644
--- a/doc/modular_congruence_multiplication_proof.tex
+++ b/doc/modular_congruence_multiplication_proof.tex
@@ -17,8 +17,6 @@
 \begin{document}
 \maketitle
 
-\section{Introduction}
-
 \newtheorem{theorem}{Theorem}
 
 %(Draft)