The Need for More Truth Values

• The undead script writing nightmare
  • Characters are alive, or dead, or undead, or have not appeared
  • All characters are alive or have been buried
  • Alive characters need words and placement
  • Dead (not alive) characters need no words but need placement
  • There are four characters:
    • Alan, who is alive
    • Désirée, who is dead and buried
    • Umberto, who is undead
    • Nigel, who has not appeared

• Questions the script writer might ask include:
  • Does Désirée need words?
  • Is Nigel alive or (inclusively) not alive?
  • Does Nigel need placement?
  • Is Umberto both alive and not alive?
  • Has Umberto been buried?
  • Was Désirée buried because she is not alive?

• TPTP syntax

• Results