xercise $2$: rst$-$order logic $(20$ points$).$ For each of the following rst$-$order logic sentences, give a concise English sentence that correctly captures their meaning $($with the obvious interpretation of At$,$ etc.$)$: $1.(5$ points$)$ x $($At$($xUCM$)$ Smart$($x$)).2.(5$ points$)$ x $($At$($xUCM$)$ Smart$($x$)).3.(5$ points$)$ x $($At$($xUCM$)$ Smart$($x$)).4.(5$ points$)$ x $($At$($xUCM$)$ Smart$($x$)).$