•propositions - T/F atomic
sentences about the world
–propositional symbols
(a.k.a. variables) P, Q, R, …, and constants True and False
–e.g. P: “There is a
mine at (1,2).”; Q: “There is a mine at
(2,2).”
•not (Ψ) - negates meaning of a sentence
–P, ΨP, Q, ΨQ, …
are called literals
–e.g. ΨQ: “There is
not a mine at (2,2)
