What do I have wrong Vital? Is it my definitions? I promise you you can look it up and see that I'm not lying about that.
Not big is not the definition of small. Not believing IS the definition of disbelieving. Your analogy is flawed.
No "not believing" IS NOT "disbelief" in the context of "not believing and disbelieving"
Just like how "Not yes" is not "no" in the context of "not yes and not no"