perl -MO=Concise,-exec -le '$x = 10;
    for(qw(moo baz bar foo)) {
        *{$_} = sub { $x + shift };
        $x-=3;
    }
    $result = foo() - bar() - baz() - moo();print $result'
1  <0> enter 
2  <;> nextstate(main 1 -e:1) v
3  <$> const[IV 10] s
4  <#> gvsv[*x] s
5  <2> sassign vKS/2
6  <;> nextstate(main 4 -e:1) v
7  <0> pushmark sM
8  <$> const[PV "moo"] sM
9  <$> const[PV "baz"] sM
a  <$> const[PV "bar"] sM
b  <$> const[PV "foo"] sM
c  <#> gv[*_] s
d  <{> enteriter(next->p last->s redo->e) lK
q  <0> iter s
r  <|> and(other->e) vK/1
e      <;> nextstate(main 3 -e:1) v
f      <0> pushmark sRM
g      <$> anoncode[CV ] lRM
h      <1> refgen sK/1
i      <#> gvsv[*_] s
j      <1> rv2gv sKRM*/1
k      <2> sassign vKS/2
l      <;> nextstate(main 3 -e:1) v
m      <#> gvsv[*x] s
n      <$> const[IV 3] s
o      <2> subtract[t5] vKS/2
p      <0> unstack v
           goto q
s  <2> leaveloop vK/2
t  <;> nextstate(main 5 -e:1) v
u  <0> pushmark s
v  <#> gv[*foo] s/EARLYCV
w  <1> entersub[t9] sKS/TARG,1
x  <0> pushmark s
y  <#> gv[*bar] s/EARLYCV
z  <1> entersub[t11] sKS/TARG,1
10 <2> subtract[t12] sK/2
11 <0> pushmark s
12 <#> gv[*baz] s/EARLYCV
13 <1> entersub[t14] sKS/TARG,1
14 <2> subtract[t15] sK/2
15 <0> pushmark s
16 <#> gv[*moo] s/EARLYCV
17 <1> entersub[t17] sKS/TARG,1
18 <2> subtract[t18] sK/2
19 <#> gvsv[*result] s
1a <2> sassign vKS/2
1b <;> nextstate(main 5 -e:1) v
1c <0> pushmark s
1d <#> gvsv[*result] s
1e <@> print vK
1f <@> leave[1 ref] vKP/REFC
-e syntax OK

##</code><code>##

$result = ( ( foo() - bar() ) - baz() ) - moo();