The effect is like executing the assignment
dst [
[
], ...,
[
]] = src []
for every tuple, 
, of global subscripts
of the source array. These assignments are executed in an undefined order.
Here 
denotest the rth subscript array.
If subs [r] is null, the value of the expression
[ 
] in the left-hand-side of the
assignment is defined to be (hence if all subscripts are undefined,
this operation is equivalent to a Remap operation).