Home / Summaries / Computational Logics for AI / flies-innocent-accused

Nonmonotonic reasoning default logic - Default logic

Q: Prototypical reaoning (def)

Most instances of a concept have some property 'typically, children have parents' child(x) : has-parents(x) __________________________ has-parents(x)

5 important questions on Nonmonotonic reasoning default logic - Default logic

brid(x): flies(x)
----------------------
flies(x)

If x is a bird and if it is consistent to assume that x flies, than conclude that x flies

Difficulties of using classical logic

All possible preconditions should be listed
usage of the rull (before applied all preconditions should be true)

Prototypical reaoning (def)

Most instances of a concept have some property

"typically, children have parents"
child(x) : has-parents(x)
__________________________
has-parents(x)

No-risk reasoning (def)

Situations where a conclusion is drawn even if it is not hte most probably becuae another decision could lead to disaster

"In absence of evidence to the contrary assume taht the accused is innocent"
accused(x) : innocent(x)
-------------------------------------
innocent(x)

A set of formulas Φ is called deductively closed

Φ = TH(Φ) = {F | Φ |= F }

Een set formules Φ is deductief gesloten als elke formule die volgt uit Φ, ook in Φ zit. Dit betekent dat Φ dezelfde formules bevat als de verzameling die wordt afgeleid uit Φ.

The question on the page originate from the summary of the following study material:

Computational Logics for AI

View summary