Reasoning conducted or assessed according to strict principles of validity; a particular system or codification of the principles of proof and inference. In the Middle Ages, logic was one of the seven liberal arts.
logic bomb in computing, a set of instructions secretly incorporated into a program so that if a particular condition is satisfied they will be carried out, usually with harmful effects.
logic chopping the practice of engaging in excessively pedantic argument. The expression chop logic is recorded from the early 16th century, and originally meant ‘exchange or bandy logical arguments’; in later use, chop was wrongly understood as meaning ‘cut, split’.