# inference algorithm is complete only if [Solved]

Question 1

Select the correct statements below and explain why

1. Propositional logic can use inference rules (consider first-order logic, does inference have to be reduced?)
2. Inference algorithms are not sound if they are complete
3. Inference algorithms can be applied to logical sentences of any form

Question 2

A It can derive any sentence

B It can derive any sentence that is an entailed version

C It is truth preserving

D It can derive any sentence that is an entailed version & It is truth preserving

Question 3

Inference algorithm is complete only if _____________

(a) It can derive any sentence

(b) It can derive any sentence that is an entailed version

(c) It is truth preserving

(d) It can derive any sentence that is an entailed version & It is truth preserving

I got this question in a national level competition.

The origin of the question is Knowledge and Reasoning in section Knowledge and Reasoning of Artificial Intelligence

A) Propositional logic can use inference rules (consider first-order logic, does inference have to be reduced?)

EXPLANATION

Propositional logic can make use of the inference rules such as modus ponen, modus tonen etc. for the computation of the result and inferences needs to be reduce to the form of the rule itself in order to use it.