$\%\%$ tests

assert$($a $==10,$ "a should be $10!")$;

assert$($b $==2500000000000,"$b should be $2\mathrm{.}5000$e$+12!")$;

assert$($abs$($c $-3\mathrm{.}73)<0\mathrm{.}05,"$c should be near $3\mathrm{.}73!")$;

assert$($exist$(\text{'}$j$\text{'}),"$j should exist $($and should be near pi$,$ or $3\mathrm{.}14)!")$;

assert$($abs$($d $-21572613)<5,"$d should be near $21572613!")$;

assert$($abs$($x $-0\mathrm{.}2781)<0\mathrm{.}05,"$x should be near $0\mathrm{.}2781!")$;

assert$($abs$($y $-9625211421428\mathrm{.}52)<10,"$y should be near $9\mathrm{.}6252$e$+12!")$;

disp$("$You have passed all the tests in this file!"$)$