Multidimensional arrays

[ghofulpo]

In which version of gawk are multidimensional arrays like:
x[3][4]
supported?  I'm running 3.1.7, and I get a syntax error on that type of 
construction.  I always had to do something like x[3 " " 4] to artificially 
construct a two dimensional array, although x[3,4] works (though I assume that 
this is treated as a single dimensional array with the index being "3,4".

James