Suppose we put into a logical knowledge base a segment of the U$.$S$.$ census data listing the age, city of

residence, date of birth, and mother of every person, using social security numbers as identifying

constants for each person. Thus, George's age is given by Age$(443-65-1282,56).$ Which of the

following indexing schemes $Sl-S5$ enable an efficient solution for which of the queries Q$1-$Q$4($assuming

normal backward chaining$)?$

S$1$: an index for each atom in each position.

S$2$: an index for each first argument.

S$3$: an index for each predicate atom.

S$4$: an index for each combination of predicate and first argument.

S$5$: an index for each combination of predicate and second argument and an index for each first

argument.

Ql: Age $-44-4321,x$

Q$2$: ResidesIn$($x$,$Houston$)$

Q$3$: Mother$(x,y)$

Q$4$: Age $(x,34{)}^{{?}^{?}}$ ResidesIn $,$ TinyTownUSA$)$Suppose we put into a logical knowledge base a segment of the U$.$S$.$ census data listing the age, city of

residence, date of birth, and mother of every person, using social security numbers as identifying

constants for each person. Thus, George's age is given by Age$(443-65-1282,56).$ Which of the

following indexing schemes $Sl-S5$ enable an efficient solution for which of the queries Q$1-$Q$4($assuming

normal backward chaining$)?$

S$1$: an index for each atom in each position.

S$2$: an index for each first argument.

S$3$: an index for each predicate atom.

S$4$: an index for each combination of predicate and first argument.

S$5$: an index for each combination of predicate and second argument and an index for each first

argument.

Ql: Age $-44-4321,x$

Q$2$: ResidesIn$($x$,$Houston$)$

Q$3$: Mother$(x,y)$

Q$4$: Age $(x,34{)}^{{?}^{?}}$ ResidesIn $,$ TinyTownUSA$)$