Some more s/Subscribable/Supply/

S17-concurrency.pod

@@ -495,7 +495,7 @@ produce an ascending value at a regular time interval.
 [TODO: many more of these, including ones for publishing a Channel and a
 Promise.]
 
-Subscribables are mathematically dual to iterators, and so it is possible to
+Supplies are mathematically dual to iterators, and so it is possible to
 define the same set of operations on them as are available on lazy lists. The
 key difference is that, while C<grep> on a lazy list I<pulls> a value to
 process, working synchronously, C<grep> on a Supply has values I<pushed>
@@ -624,7 +624,7 @@ loop that would be underlying all concurrency.  In this version, this is not
 the case.
 
 Instead, most system level events, be they POSIX signals, or specific OS events
-such as file updates, will be exposed as C<Subscribables>.  For instance,
+such as file updates, will be exposed as a C<Supply>.  For instance,
 $*POSIX is a Supply in which POSIX signals received by the running
 process, will appear as C<POSIX::Signal> objects to taps.  On
 non-POSIX systems, a similar Supply will exist to handle system events.