\exists\,x\;\;} {Dog}(x) {\:\;{\Rightarrow}\:\;}({\exists\,y\;\;} {Child}(y,{Owner}(x)) \land {Bites}(x,y))$.<br />

4.  Everyone’s zip code within a state has the same first digit.<br />

    1.  ${\forall\,x,s,z_1\;\;} [{State}(s) \land {LivesIn}(x,s) \land {Zip}(x)z_1] {\:\;{\Rightarrow}\:\;}{}$\
        $[{\forall\,y,z_2\;\;} {LivesIn}(y,s) \land {Zip}(y)z_2 {\:\;{\Rightarrow}\:\;}{Digit}(1,z_1) {Digit}(1,z_2) ]$.<br />

    2.  ${\forall\,x,s\;\;} [{State}(s) \land {LivesIn}(x,s) \land {\exists\,z_1\