[sv-bc] Interpretation of typedefed packed-unpacked array

Hello

Consider the example

typedef bit [0:2] a [1:0];
a [3:0] b [2:0];

Is it a legal syntax. 3.1a LRM is not having any suitable explanation 
for this kind of example. In this a is a representation of a array, and 
b is a array of type a.
 
     Will this mean that b will be treated as bit  [3:0][0:2]b[1:0][2:0] 
as an extention to 'a '.  Or it will be an error as a packed array 
cannot be created from an unpacked element, but will it be valid to 
consider a as array.

Thanks
Rakesh Gulati