sub a {
 b(@_)
}
 
sub b {
 return map { $_ +1 }  @_;
}
 
print a (1,2,3)

##</code><code>##

perl -d tst.pl
Loading DB routines from perl5db.pl version 1.3
Editor support enabled.
 
Enter h or `h h' for help, or `man perldebug' for more help.
 
Package /tmp/tst.pl.
 DB<3> o f=31
              frame = '31'
 DB<4> c
in  @=main::a(1, 2, 3) from /tmp/tst.pl:9
 in  @=main::b(1, 2, 3) from /tmp/tst.pl:2
 out @=main::b(1, 2, 3) from /tmp/tst.pl:2
 list context return from main::b:
0  2
1  3
2  4
out @=main::a(1, 2, 3) from /tmp/tst.pl:9
list context return from main::a:
0  2
1  3
2  4