For ten points, name this type of logic whose name describes its imprecise view of quantities.
Formulated by Lotfi Zadeh in 1965, it's employed in robotic control and pattern recognition software.  Rejecting the law of the excluded middle, it instead asserts that variables --- tallness for instance --- have levels of truthfulness and uses "if x and y then z" rules to plan the system response.  For ten points, name this type of logic whose name describes its imprecise view of quantities.
Formulated by Lotfi Zadeh in 1965, it's employed in robotic control and pattern recognition software.  
fuzzy logic