PostgreSQL Array Syntax

Good afternoon.

I am attempting to create a PHP script that inserts values into a 
PostgreSQL database, where some of the columns are two dimensional 
arrays. I read the docs and it says that array elements must be matched 
and that is what I am confused about. Does that mean that 
ARRAY[['eng_labs'], ['eng_labs', 'mst_labs', 'ics_labs']] is incorrect 
array syntax? If so, I am assuming that the way to correct it would be:
ARRAY[['eng_labs', '', ''], ['eng_labs', 'mst_labs', 'ics_labs']]. Thus, 
each multidimensional array must have values in place for the largest 
element, correct?

Thank you for your time
Evan Klinger
-- 
Evan Klinger
Network & Academic Computing Services
Research Computing Support
University of California, Irvine