```Date: Dec 11, 2012 9:26 PM
Author: fom
Subject: Re: fom - 02 - CORRECTED - 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-NOTline elements-NOT OTHER NO SOME ALLContraposition:axis-NOTline elements-NOT LEQ XOR NTRU TRUConjugation:axis-NOTline elements-NOT 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:     {NOT, NO, OTHER, ALL, SOME}NOT:      {NOT,   NTRU, LEQ,  XOR,  TRU}LEQ:      {NOT,   IF,   NIMP, IMP,  NIF}XOR:      {NOT,   OR,   NAND, AND,  NOR}TRU:      {NOT,   FLIP, LET,  DENY, FIX}NO:       {NO,    NTRU, IF,   OR,   FLIP}IF:       {NO,    LEQ,  NIMP, NAND, LET}OR:       {NO,    XOR,  IMP,  AND,  DENY}FLIP:     {NO,    TRU,  NIF,  NOR,  FIX}OTHER:    {OTHER, NTRU, IMP,  NAND, FIX}IMP:      {OTHER, LEQ,  NIF,  OR,   DENY}NAND:     {OTHER, XOR,  IF,   NOR,  LET}FIX:      {OTHER, TRU,  NIMP, AND,  FLIP}ALL:      {ALL,   NTRU, NIMP, NOR,  DENY}NIMP:     {ALL,   LEQ,  IF,   AND,  FIX}NOR:      {ALL,   XOR,  NIF,  NAND, FLIP}DENY:     {ALL,   TRU,  IMP,  OR,   LET}SOME:     {SOME,  NTRU, NIF,  AND,  LET}NIF:      {SOME,  LEQ,  IMP,  NOR,  FLIP}AND:      {SOME,  XOR,  NIMP, OR,   FIX}LET:      {SOME,  TRU,  IF,   NAND, DENY}===========================================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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