 Fuzzy logic is intended to model logical reasoning with vague or imprecise statements like “Petr is young (rich, tall, hungry, etc.)”. It refers to a family of  many-valued logics,  where the truth-values are interpreted as degrees of truth. The truth-value of a logically compound proposition, like “Carles is tall and Chris is rich”, is determined by the truth-value of its components. In other words, like in classical logic, one imposes truth-functionality.