chapter 7

Question 1

What is bottom-up grounding?

Answer 1

To Ground relevant rules by gradually extending the atom base

Question 2

What is a relavent rule?

Answer 2

when each positive body literal has a non-cyclic derivation
(ignoring negative literals)

Question 3

Why is bottom-up Grounding in-efficient?

Answer 3

• Re-grounds rules from previous steps
• Performs no simplifications

Question 4

How do you Perform simplifications during grounding?

Answer 4

• remove literals from rule bodies if possible
• omit rules if body cannot be satisfied

Question 5

What does it mean when a rule depends on another?

Answer 5

If the body literals of rule 2 unify with the head elements in rule1.
if b ∈ B(r2) + ∪ B(r2)
− unifies with h ∈ h(r1)

Question 6

What does foreach C in LP mean?

Answer 6

For each Component in a strongly connected component set.

Question 7

Semi Naive grounding.

Answer 7

Semi Naive grounding originates from database systems [1])
To avoid recomputing the same atoms at each level,
semi-naive grounding focuses on newly generated atoms:
Any new atom at step i relies on at least one atom
newly derived at step i − 1

Question 8

In relation to prepared rules, what are o, a, and n?

Answer 8

In relation to prepared rules, O is old, A is all, and n is New. You can only have one new atom with each iteration.

Question 9

Which of the following algorithms only ground relevant rules?

Answer 9

Bottom Up and Semi Naive

Question 10

Bottom Up grounding regrounds rules many times

Answer 10

True

Question 11

You can use a dependency graph to reduce the number of rules that are reground, but we still reground some rules.

Answer 11

True

Question 12

When we simplify a rule on the fly, we remove positive body literals we are sure that are true

Answer 12

True

Question 13

When we simplify on the fly we remove negative body literals we are sure are true.

Answer 13

False, we remove the positive ones.