From 9a09ff821f48555859f9b74da30f94b85ad2c2fa Mon Sep 17 00:00:00 2001
From: Yousri <54667@etu.he2b.be>
Date: Tue, 10 May 2022 16:08:05 +0200
Subject: [PATCH] Quote Added

---
 Intro_to_Solid.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Intro_to_Solid.md b/Intro_to_Solid.md
index e668b80..a2c228c 100644
--- a/Intro_to_Solid.md
+++ b/Intro_to_Solid.md
@@ -336,3 +336,6 @@ You have to create a new mother class for these two classes like the preceding e
 
 This convention says that all classes that we use depends on the interface or abstract classes.
 Like precedents example, all methods was abstracts.
+
+>The Dependency Inversion principle states that our classes should depend upon interfaces or abstract classes instead of concrete classes and functions.
+>We want our classes to be open to extension, so we have reorganized our dependencies to depend on interfaces instead of concrete classes.
\ No newline at end of file