(from the article `applied logic`) ... = ~ ~ . Several nonequivalent systems have been developed by the conceptual pragmatist C.I. Lewis (1883–1964), primary author of Symbolic Logic ... Found on http://www.britannica.com/eb/a-z/s/198
a modern development of formal logic employing a special notation or symbolism capable of manipulation in accordance with precise rules. Also called Found on https://www.infoplease.com/dictionary/symbolic-logic