This paper analyzes some of the major sources of error which account f
or variations in performance among the 72 logical systems studied in [
2, 4, 5]. One of the most important of these sources is discretization
error. We show that a new approach to implementing logical systems ba
sed on level sets is a powerful and efficient way to control discretiz
ation error for material implication relations, though it produces mix
ed results under Mamdani logic.