In BELNAP and SI'ENCER, 1964, there was also introduced the notion of an ..... ordering principle, let Yo be the first such element y, and let z o be the first such.
DUNN, J. M., and N. D. BELNAPJR. Math. Annalen 176, 28--38 (J968)
Homomorphisms of Intensionally Complemented Distributive L a t t i c e s * J. M. DUNN and N. D. BELNAP, JR. §t In BELNAP and SPENCER, 1964, there was introduced the notion of an intensionatty complemented distributive lattice with truth-filter (icdI w/t-f) as a quadruple (A,
