"contradiction"

I was asked about the definition of "contradiction" in math or logic. Roughly speaking, it's defined that both a proposition A and denied proposition A' are true. In Japanese math class, we face it in junior highschool or highschool in the context that "prove that square root of 2 is irrational number."

In explaining it, I found that the word "contradiction" decomposes 3 parts: "contra"+"dict"+"ion." Let us review in French.

-"contra" comes from a preposition "contre" in French, and it means like "against" in English.
-"dict" comes from the verb "dire" in French, and it's "say" in English.
-"ion" is used in creating femenine noun in French. We can find many nouns finishing "-ion" in English, and they originate French words, in general. (ex. information, installation, and so on..)

In Japanese, we say "Mu-jun" for the word "contradiction." "Mu" is sword and "Jun" is shild, and it seems to originate in Chinese.