$1: VARSET X 2
$2: VARSET Y 5
$3: VARSET Z $4
  $4: ADD $5 $6
    $5: VARGET X
    %5=2
    $6: VARGET Y
    %6=5
  %4=7
$7: VARSET A $8
  $8: CALL sqrt $9
    $9: VARGET Z
    %9=7
  %8=2.6457513110646
$10: VARSET B $11
  $11: EXP $12 2
    $12: VARGET A
    %12=2.6457513110646
  %11=7
$13: SUB $14 $15
  $14: VARGET B
  %14=7
  $15: VARGET Y
  %15=5
%13=2
2