>perl -MO=Concise -e"my $x = 1; $x += 2; print $x"
e  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 1 -e:1) v ->3
5     <2> sassign vKS/2 ->6
3        <$> const[IV 1] s ->4
4        <0> padsv[$x:1,2] sRM*/LVINTRO ->5
6     <;> nextstate(main 2 -e:1) v ->7
9     <2> add[t2] vKS/2 ->a
7        <0> padsv[$x:1,2] sRM ->8
8        <$> const[IV 2] s ->9
a     <;> nextstate(main 2 -e:1) v ->b
d     <@> print vK ->e
b        <0> pushmark s ->c
c        <0> padsv[$x:1,2] l ->d
-e syntax OK