Remove stray "introduction" section.
diff --git a/doc/modular_congruence_multiplication_proof.pdf b/doc/modular_congruence_multiplication_proof.pdf
index 83c6dc1..e2207df 100644
--- a/doc/modular_congruence_multiplication_proof.pdf
+++ b/doc/modular_congruence_multiplication_proof.pdf
Binary files differ