More humorous than truly obfuscated. Credit to Andrew Pimlott on fwp@perl.org.

Is is obvious to you how this works? 

#!/usr/bin/perl -wl
use constant FALSE, !TRUE;
use constant TRUE, !FALSE;
use strict;

print "false is \"", FALSE, "\" in string context";
print "false is ", 0+FALSE, " in numeric context";
print "true is ", TRUE;
__END__
output:
false is "" in string context
false is 0 in numeric context
true is 1

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Update: the print statements are only intended to demonstrate that the constants created act like perl's built in boolean return values (where false is dual-valued as 0 and ""). There's nothing complex about them.

In reply to circular boolean constants by ysth

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