formal logic

WordReference Random House Unabridged Dictionary of American English © 2026

for′mal log′ic, 

1. Philosophy the branch of logic concerned exclusively with the principles of deductive reasoning and with the form rather than the content of propositions.

• 1855–60

Collins Concise English Dictionary © HarperCollins Publishers::

formal logic noun

1. Also called: symbolic logic the study of systems of deductive argument in which symbols are used to represent precisely defined categories of expressions