Fuzzy logic has a much wider and deeper foundation than is implied in thispractical text. To learn a new language one can study the grammar or learn byexamples. Professional engineers and students with time constraints would usuallyopt for the latter method and this is the aim in both this and the companion text,An Introduction to Fuzzy Logic Applications. The benefits of the newlanguage are;more flexibility and generality in the formulation and solution of problems; nonlinearproblems are easily encompassed. Also input information is often more fullyrepresented than in conventional treatments and furthermore carried through to theconclusions which consequently have a higher information content. This is a keyfactor, enabling more reliable decisions to be made by professional engineers anddesigners.This work extends and complements that the companion text. It opens up newavenues of applications and new aspects of fuzzy logic. There is a stronger emphasison the interpretation of the conclusions.