DB<1> use charnames qw(greek)

  DB<2> print "\N{alpha}"
Use of uninitialized value $txt in pattern match (m//) at /usr/opt/perl5/lib/5.20.1/_charnames.pm line 459.
 [...]
Unknown charname 'alpha' at (eval 9)[/usr/opt/perl5/lib/5.20.1/perl5db.pl:732] line 2, within string

  DB<3> print "\N{U+03B1}"
Wide character in print at (eval 10)[/usr/opt/perl5/lib/5.20.1/perl5db.pl:732] line 2.
 [...]
&#945;

  DB<4> print "\N{greek:alpha}"  
Use of uninitialized value $txt in pattern match (m//) at /usr/opt/perl5/lib/5.20.1/_charnames.pm line 459.
 [...]
Unknown charname 'greek:alpha' at (eval 11)[/usr/opt/perl5/lib/5.20.1/perl5db.pl:732] line 2, within string