Knowledge Systems Laboratory, Stanford
University
12
Truth Value
uDenote “truth value” by “TIV”
8I is an interpretation
8V is a variable assignment
uLogical constants
8Tiv(<constant>)
= I(<constant>)
8Tiv(true) = true
8Tiv(false) = false
uTruth value of a relational sentence
8TIV((rel term1 … termn)) =
>true when áSIV(term1), … , SIV (termn)ń is a member of set I(rel)
>false otherwise
8TIV((rel term1 … termn @var)) =
>true when áSIV (term1), … , SIV (termn) | SIV (@var)ń is a member of set
I(rel)
>false otherwise