On the Concept "Contradiction" in Dialectic

In the finst place, I tried to make the meaning of the word dialectical "Contradiction" clear. It seems to me there are two usages of that term. The first, the contradiction in existence. The second, the contradiction in logical. It is my principal purpose in this two subject how we can get no contradiction.In my opinion, to find the contradiction in existence consists of Aristotle's principle of contradiction. As to the methodology of the expressional contradiction, for "Real Existence, " I took the cases of ideal dialectic and material dialectic, and analysed the relation between their expressional contradiction.