Defuzzification nonmonotonicity in material implication logics

We attempt to demonstrate the nonmonotonicity in material implication fuzzy logics, explain its source, and seek remedies. Alternatives to Mamdani logic systems have not shared the research effort afforded to the very successful Mamdani systems and their extensions for fuzzy controllers. We consider a special member of the family of t-norm logic systems with special emphasis on defuzzification methods that apply. With special care, a Kleene-Dienes controller may find favor in future applications