DB<110> @records= (["amy", 35], ["bill", 35], ["george", 28], ["jason", 35])
 => (["amy", 35], ["bill", 35], ["george", 28], ["jason", 35])

  DB<111> sub cmp_age { $::a->[1] <=> $::b->[1] }

  DB<112> sub cmp_name { $::a->[0] cmp $::b->[0] }

  DB<113> sort {cmp_age or cmp_name} @records 
 => (["george", 28], ["amy", 35], ["bill", 35], ["jason", 35])

  DB<114> sort {cmp_age or - cmp_name} @records 
 => (["george", 28], ["jason", 35], ["bill", 35], ["amy", 35])