Definition of parallelogram:
The attribute, therefore, of having the opposite sides equal, is a Proprium of the class parallelogram; and a Proprium of the first kind, which follows from the connoted attributes by way of demonstration.- "A System Of Logic, Ratiocinative And Inductive (Vol. 1 of 2)", John Stuart Mill.
- "The Memoires of Casanova, Complete The Rare Unabridged London Edition Of 1894, plus An Unpublished Chapter of History, By Arthur Symons", Jacques Casanova de Seingalt.
- "John Deere's Steel Plow", Edward C. Kendall.