Fuzzy inference has a multi-granular architecture consisting of symbols and continuous values, and this architecture has worked well to incorporate experts' know-how into fuzzy controls. Stability analysis of fuzzy control system is one of the main topics of fuzzy control. Recently, a stability analysis method on symbolic level has been proposed. This method opened the door to the design of stable fuzzy controller using symbols. This paper presents a new fuzzy inference method that makes the relaxed condition applicable to the fuzzy control systems with asymmetric membership functions.