system of rules, system - a complex of methods or rules governing behavior; "they have to operate under a system they oppose"; "that language has a complex system for indicating gender"

Aristotelian logic - the syllogistic logic of Aristotle as developed by Boethius in the Middle Ages

formal logic, mathematical logic, symbolic logic - any logical system that abstracts the form of statements away from their content in order to establish abstract criteria of consistency and validity

extrapolate - gain knowledge of (an area not known or experienced) by extrapolating

induce - reason or establish by induction

deduce, derive, infer, deduct - reason by deduction; establish by deduction

negate, contradict - prove negative; show to be false

elicit - derive by reason; "elicit a solution"