Atomization in Unary Lookup

Could I please just check that for

? ParenthesizedExpr

It is intentional that atomization happens as

for $k in KS
return .(fn:data($k))

and not

for $k in fn:data(KS)
return .($k)

In the former case

[1, 2, 3]?[1,2]

is an error, while in the latter case it would return (1, 2).

Thanks,
     Tim