$\alpha_2$ = “There is no pit in [2,2].”
$\alpha_3$ = “There is a wumpus in [1,3].”
Hence show that ${KB} {\models}\alpha_2$ and ${KB} {\models}\alpha_3$.
Suppose the agent has progressed to the point shown in
Figure wumpus-seq35-figure(a), page wumpus-seq35-figure,
having perceived nothing in [1,1], a breeze in [2,1], and a stench
in [1,2], and is now concerned with the contents of [1,3], [2,2],
and [3,1]. Each of these can contain a pit, and at most one can
contain a wumpus. Following the example of
Figure wumpus-entailment-figure, construct the set of
possible worlds. (You should find 32 of them.) Mark the worlds in which
the KB is true and those in which each of the following sentences is
true:
$\alpha_2$ = “There is no pit in [2,2].”
$\alpha_3$ = “There is a wumpus in [1,3].”
Hence show that ${KB} {\models}\alpha_2$ and
${KB} {\models}\alpha_3$.