```Date: Dec 7, 2012 2:08 AM
Author: fom
Subject: fom - 02 - logical constants

What follows it the presentation oflogical constants in the form of aprojective geometry on 21-names.The namespace conforms with a typicalpresentation of finite projectivegeometries using difference sets.There are three collineations whichshall be named:Negation:axis-THISline elements-THIS SOME OTHERS NO ALLContraposition:axis-THISline elements-THIS LEQ XOR NTRU TRUConjugation:axis-THISline elements-THIS FLIP LET DENY FIXAll admissible projectivities for the dual planeshall fix these lines.The list that follows takes the form:Line Name: {list of line elements}A 21-point projective plane has 21 lines:NTRU:     {THIS, SOME, OTHER, NO, ALL}THIS:     {THIS, NTRU, LEQ, XOR, TRU}LEQ:      {THIS, IF, NIMP, IMP, NIF}XOR:      {THIS, OR, NAND, AND, NOR}TRU:      {THIS, FLIP, LET, DENY, FIX}SOME:     {SOME, NTRU, IMP, NAND, FIX}IMP:      {SOME, LEQ, NIF, OR, DENY}NAND:     {SOME, XOR, IF, NOR, LET}FIX:      {SOME, TRU, NIMP, AND, FLIP}OTHER:    {OTHER, NTRU, IF, OR, FLIP}IF:       {OTHER, LEQ, NIMP, NAND, LET}OR:       {OTHER, XOR, IMP, AND, DENY}FLIP:     {OTHER, TRU, NIF, NOR, FIX}NO:       {NO, NTRU, NIF, AND, LET}NIF:      {NO, LEQ, IMP, NOR, FLIP}AND:      {NO, XOR, NIMP, OR, FIX}LET:      {NO, TRU, IF, NAND, DENY}ALL:      {ALL, NTRU, NIMP, NOR, DENY}NIMP:     {ALL, LEQ, IF, AND, FIX}NOR:      {ALL, XOR, NIF, NAND, FLIP}DENY:     {ALL, TRU, IMP, OR, LET}===========================================A difference set presentation is given by:18:       {0, 9, 11, 4, 3}0:        {0, 18, 8, 6, 1}8:        {0, 10, 19, 13, 14}6:        {0, 16, 12, 2, 15}1:        {0, 7, 17, 5, 20}9:        {9, 18, 13, 12, 20}13:       {9, 8, 14, 16, 5}12:       {9, 6, 10, 15, 17}20:       {9, 1, 19, 2, 7}11:       {11, 18, 10, 16, 7}10:       {11, 8, 19, 12, 17}16:       {11, 6, 13, 2, 5}7:        {11, 1, 14, 15, 20}4:        {4, 18, 14, 2, 17}14:       {4, 8, 13, 15, 7}2:        {4, 6, 19, 16, 20}17:       {4, 1, 10, 12, 5}3:        {3, 18, 19, 15, 5}19:       {3, 8, 10, 2, 20}15:       {3, 6, 14, 12, 7}5:        {3, 1, 13, 16, 17}
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