use the example above to solve the following question.

Draw the and/or graph for this set of predicate calculus statements. Then show the substitutions you can make to answer the question, "Who helps David?" The format required for and/or graphs and substitutions is shown on the example above. Note that if more than one person helps David, you will need to show the substitutions for each one separately. (Hint: Double check your work to make sure you are not answering the different question, "Who does David help?")

Predicate Calculus Example Example of Goal-Driven Search in an And/Or Tree 1. Fred is a collie collie(fred) w location( fred, W) Where's Fred? 2. Sam is Fred's master. master(fred,sam) The day is Saturday day(saturday). location (X,Z) Direction of search 3. . It is cold on Saturday warm (saturday) Fred is trained. trained(fred) Spaniels are good dogs and so are trained collies. gooddog(X) master(X,Y) location(Y,Z) 5. 6. X[spaniel(X) v (collie(X) ^ trained(X))-> gooddog(X)) If a dog is a good dog and has a master then he will be with his master collie(X) trained(X) master(fred,sam) day(saturday) warm (Saturday) 7. (XYZ) [gooddog(X) ^ master(X,Y) location(Y,Z) If it is Saturday and warm, then Sam is at the park. (day(saturday) A warm(saturday))-location(sam,park) If it is Saturday and not warm, then Sam is at the museum. (day(saturday)(warm(saturday))location(sam,museum) location(X,Z)] 8. collie(fred) trained(fred) 9. Substitutions (fred/x, sam/Y, museum/Zy Consider the following sentences and their associated predicate calculus statements: 1. Neighbors help each other. 2. Siblings help each other. 3. People who live on the same street are neighbors. 4. People who have the same parents are siblings y X y Y (neighbor(X,Y)-> helps(X,Y)) VXV Y (sibling(X,Y) - helps(X,Y)) y X V ((lives-on(XZ) ^ lives_on(YZ)) neighbor(X,Y)) 5. David lives on Court Street. 6. Anita is David's parent. 7. Anita is Kate's parent. 8. Lee lives on Court Street. X V V (parent(ZX) ^ parent(Z,Y)) sibling(X,Y)) lives on(david, court_ street) parent(anita, david) parent(anita, kate) lives on(lee, court_street)