some problems of DL Reasoning

I am new to the Description Logics. I have met the following problem.

As we know, K |= C <==> ¬C unsatisfiable with K,
here K is a DL knowledge base, and C is a concept

If K is set to {A,B}, and C is set to ¬(A∧¬B), then ¬C is unsatisfiable with
K
it means K|=A subclassof B

using the similar way, we  can also get K|=B subclassof A,

I must be missing something obvious here. Can someone can tell me the reason

Thank you for any comments!


-- 
Best Regards!

Jun Fang - PhD candidate,
Control & Networks Institute,
College of Automation,
Northwestern Polytechnical University,
Xi'an, Shaanxi Province, China
E-mail:leon.essence@gmail.com