# MCQ-Inference in First-Order Logic-AI Posted by

The "Answers" given with the Question is "not verified". To view Verified answers click on the button below.

Inference in First-Order Logic

1. The rule of Universal Instantiation (UI for short) says that we can infer any sentence obtained by substituting a ground term (a term without variables) for the variable.
a) True
b) False
Explanation: Rule of universal instantiation.

2. The corresponding Existential Instantiation rule: for the existential quantifier is slightly more complicated. For any sentence a, variable v, and constant symbol k that does not appear elsewhere in the knowledge base.
a) True
b) False
Explanation: Rule of existential instantiation.

3. What among the following could the universal instantiation of ___________ For all x King(x) ^ Greedy(x) => Evil(x)
a) King(John) ^ Greedy(John) => Evil(John)
b) King(y) ^ Greedy(y) => Evil(y)
c) King(Richard) ^ Greedy(Richard) => Evil(Richard)
d) All of the mentioned
Explanation: Refer the definition if universal instantiation.

4. Lifted inference rules require finding substitutions that make different logical expressions looks identical.
a) Existential Instantiation
b) Universal Instantiation
c) Unification
d) Modus Ponen
Explanation: None.

5. Which of the following is not the style of inference?
a) Forward Chaining
b) Backward Chaining
c) Resolution Refutation
d) Modus Ponen
Explanation: Modus ponen is a rule for an inference.

6. In order to utilize generalized Modus Ponens, all sentences in the KB must be in the form of Horn sentences.
a) True
b) False
Explanation: None.

7. For resolution to apply, all sentences must be in conjunctive normal form, a conjunction of disjunctions of literals.
a) True
b) False
Explanation: None.

8. What are the two basic types of inferences?
a) Reduction to propositional logic, Manipulate rules directly
b) Reduction to propositional logic, Apply modus ponen
c) Apply modus ponen, Manipulate rules directly
d) Convert every rule to Horn Clause, Reduction to propositional logic
Explanation: None.

9. Which among the following could the Existential instantiation of ∃x Crown(x) ^ OnHead(x, Johnny)?
b) Crown(y) ^ OnHead(y, y, x)