use strict;
package A;

sub new {
	my $pkg = shift;
	bless {}, $pkg;
}

sub first {
	print "A::first\n";
}

sub second {
	print "A::second\n";
}
sub check {
	my $this = shift;
	my $pkg = ref $this;
	print "\nResults of check:\n";
	foreach my $subname (qw(first SUPER::first second SUPER::second)) {
		if (defined (my $sub = $this->can ($subname))) {
			print ("$pkg can $subname\n");
			$this->$sub ();
		}
		else {
			print "$pkg cannot do $subname\n";
		}
	}	
}


package A_sub;
@A_sub::ISA = qw(A);

sub first {
	print "A_sub::first\n";
}	

sub check_sub {
	my $this = shift;
	my $pkg = ref $this;
	print "\nResults of check_sub:\n";
	foreach my $subname (qw(first SUPER::first second SUPER::second)) {
		if (defined (my $sub = $this->can ($subname))) {
			print ("$pkg can $subname\n");
			$this->$sub ();
		}
		else {
			print "$pkg cannot do $subname\n";
		}
	}	
}


package main;
my $asub = new A_sub;
$asub->check ();
$asub->check_sub ();

##</code><code>##


Results of check:
A_sub can first
A_sub::first
A_sub cannot do SUPER::first
A_sub can second
A::second
A_sub cannot do SUPER::second

Results of check_sub:
A_sub can first
A_sub::first
A_sub can SUPER::first
A::first
A_sub can second
A::second
A_sub can SUPER::second
A::second