Of course it is, its exactly the same. If you keep hitting delete, you'll even get the same error message.

page 0 does not exist at tk.notebook.add.delete.pl line 20
page -1 does not exist at tk.notebook.add.delete.pl line 20
page -2 does not exist at tk.notebook.add.delete.pl line 20
page -3 does not exist at tk.notebook.add.delete.pl line 20
page -4 does not exist at tk.notebook.add.delete.pl line 20
page -5 does not exist at tk.notebook.add.delete.pl line 20
page -6 does not exist at tk.notebook.add.delete.pl line 20
page -7 does not exist at tk.notebook.add.delete.pl line 20
page -8 does not exist at tk.notebook.add.delete.pl line 20
page -9 does not exist at tk.notebook.add.delete.pl line 20
page -10 does not exist at tk.notebook.add.delete.pl line 20
page -11 does not exist at tk.notebook.add.delete.pl line 20
page -12 does not exist at tk.notebook.add.delete.pl line 20
[download]

You don't provide enough code to figure out why nmap3 doesn't exist