Delegating nested subdomains

[Mikos Jobanx]

Hi,
this is kind of a fundamental / theoretical question, but anyways - is it
legal / allowed to delegate 'subdomains of an subdomain' into different
authoritative name servers, in one zone?

For example in the zone file for example.com:

foo.example.com IN NS ns.alpha.tld.
one.foo.example.com IN NS ns.gamma.tld.
host.one.foo.example.com IN NS ns.omega.tld.


In other words:

as the first NS record says that "everything under the domain
foo.example.com can be found from name server at ns.alpha.com"  --  is it
legal to say next line that "oh, by the way, having said that, all the
records under one.foo.example.com are located elsewhere (ns.gamma.tld)". And
so on...

Thanks,

-mjobanx