March 6, 2024
March 7, 2024
March 6, 2024
###### Question 5926 – UGC NET CS 2009-June-Paper-2
March 7, 2024

Consider the following two sentences :
(a) The planning graph data structure can be used to give a better heuristic for a planning problem.
(b) Dropping negative effects from every action schema in a planning problem results in a relaxed problem.
Which of the following is correct with respect to the above sentences ?

Question 89 Explanation:
● Negative effects put restrictions on the action schema. When these restrictions are put into place, then the number of actions that can be taken to get to the next time step decreases because with each addition of a restriction, the actions that do not meet the
restriction are filtered out.
● When these negative effects are dropped, then the number of actions increase and dropping all of the negative effects from the action schema results in a relaxed problem.
● A planning graph is a directed graph organized into levels: first a level S​ 0​ for the initial state, consisting of nodes representing each fluent that holds in S​ 0​ ; then a level A​ 0 consisting of nodes for each ground action that might be applicable in S​ 0​ ; then
alternating levels S​ i​ followed by A​ i​ ; until we reach a termination condition
● As a tool for generating accurate heuristics, we can view the planning graph as a relaxed problem that is efficiently solvable
Both sentence (a) and sentence (b) are false.
Both sentence (a) and sentence (b) are true.
Sentence (a) is true but sentence (b) is false
Sentence (a) is false but sentence (b) is true.