Alias problem

[korte]

I would like to define an array.
16-bit 32-bit elements.
This works well.

I would like to name the first 8 elements in the array to another array of items, and other elements of an array of registers.

type ARR is array (15 downto 0) of std_logic_vector(31 downto 0);
signal regs : ARR;

alias  w: ARR is regs(7 downto 0);
alias aa: is regs(8);
alias ab: is regs(9);
alias ac: is regs(10);
.
.
alias ag: is regs(15);