Fill in "arguments" section, and link to Capture

lib/Language/functions.pod

@@ -96,9 +96,29 @@ L<documentation on the C<Signature> class|Signature>.
 
 =head2 Arguments
 
-TODO
-=comment prefix:<|>, pair-chaining, \()
-
+When calling a function, positional arguments should be supplied
+in the same order as the function's signature.  Named arguments
+may be supplied in any order, but it is considered good form to
+place named arguments after positional arguments.  Inside the
+argument list of a function call, some special syntax is supported:
+
+    f :named(35)     # A named argument (in "adverb" form.)
+    f named => 35    # Also a named argument.
+    f :35named       # A named argument using abbreviated adverb form
+    f 'named' => 35  # Not a named argument, a Pair in a positional argument
+    f |$c            # Merge the contents of Capture $c as if they were supplied
+    
+Arguments passed to a function are conceptually first collected in a
+C<Capture> container.  Details about the syntax and use of these
+containers can be found in the L<documentation on the C<Capture> class|Capture>.
+
+When using named arguments, note that normal List "pair-chaining" allows
+one to skip commas between named arguments.
+
+    f :dest</tmp/foo> :src</tmp/bar> :lines(512)
+    f :32x :50y :110z   # This flavor of "adverb" works, too
+    f :a:b:c            # The spaces are also optional.
+    
 =head2 Multi-dispatch
 
 Perl 6 allows you to write several routines with the same name, but different