When embedding a command in a subshell "( ... )" avoid accidentally
producing (( (when the cmd starts with a '(' as that as a reserved
sequence (according to posix) and some shells do treat it specially.
So, force a space after the enclosing '(' to avoid the problem.
For symmetry, put a space before the concluding ')' as well, though
there is nothing special about )). (from kre@)

(christos)