Re^3: I thought I found a bug of Perl

[eyepopslikeamosquito]

> I wish I can delete the post

From How do I change/delete my post?

PerlMonks is a place to learn. As often happens in real life, Perl Monks learn (and often learn best) from mistakes that they and others have made. If you make a mistake in a node and then delete it, you may be saving your pride but you are also depriving your fellow Monks of the chance to learn from the mistake. Only actual duplicates, spam, and obvious trolling should be deleted.

See also How do I compose an effective node title? which advises:

As a general rule, refrain from changing the title of a reply node unless you're actually changing the subject ... If, after careful consideration, you decide that a mid-thread title change is appropriate, please at least retain part of the original title, including the "Re^$x:" part.