Generators with @inlineCallbacks?

test.py

from time import sleep

from twisted.internet import reactor
from twisted.internet.defer import inlineCallbacks
from twisted.internet.task import deferLater


@inlineCallbacks
def a():
    yield deferLater(reactor, 1, lambda: None) # Now the blocking function is made async, we need to yield it.
    for i in xrange(10):
        yield i

# note NO inlinecallbacks
def a1():
    sleep(1) # suppose this is a blocking function
    for i in xrange(10):
        yield i

@inlineCallbacks
def b():

    d = yield a1()
    print d
    b = d.next()
    print b

    d = yield a() # We yield the deferred from the @inlineCallbacks
    print d # None - I expect this to be a generator object or the int itself
    b = d.next() # Crashes? Why doesn't this give me 0 ?
    print b

@inlineCallbacks
def c():
    yield b()
    reactor.stop()

reactor.callWhenRunning(c)
reactor.run()