http://quod.lib.umich.edu/d/did/ Encyclopedia of Diderot & d'Alembert - Collaborative Translation Project http://hdl.handle.net/2027/spo.did2222.0002.881 ) 2021-07-14 Equation in algebra signifies an expression of the same quantity presented in two different forms. See Equality. Encyclopedia of Diderot & d'Alembert - Collaborative Translation Project