"Enter the first number: "  print
expect trim  1.1 prefer as $a
"Enter the second number: " print
expect trim  1.1 prefer as $b

$a $b < if  $b $a "%g is less than %g\n" print
$a $b > if  $b $a "%g is greater than %g\n" print
$a $b = if  $b $a "%g is equal to %g\n" print