Negation as Failure and Logical Negation
- Negation as Failure (NAF) - is a non-monotonic inference rule, used to derive not p (p is assumed not to hold) from failure to derive p
- Logical Negation - ¬p is the logical negation of p
Negation as Failure and Logical Negation: Combined
- ¬p ← not p (¬p holds by default - closed world assumption)
- p ← not ¬p (p holds by default - argument from ignorance)
Classical Negation - Default Negation - Negation as Failure (NAF) - Logical Negation
|
Name |
syntax |
semantics |
|---|---|---|
|
p |
p is true | |
|
not ¬p |
p is maybe true | |
|
not ¬p ʌ not p |
p is unknown | |
|
not p |
p is maybe false | |
|
¬p |
p is false |