@r = () ;
  @r = undef ;               # sets $r[0] = undef 
  @r = 1234 ;
  @r = (12, 23, 34, 45) ; 
  @r = 'a'..'z' ;
  @s = ('a'..'z')[4..15] ;
  @t = @r[7..16];
  @q = 9..13 ;
  @u = @r[@q] ;
  @r{'a'..'z'} = (1..26) ;
  @w = @r{'k'..'p'} ;
  @p = 'k'..'p' ;
  @w = @r{@p} ;