PEP 572: Mention another alternate syntax

pep-0572.rst

@@ -330,6 +330,15 @@ Broadly the same semantics as the current proposal, but spelled differently.
    is repurposed (most likely ``with:``).  See PEP 3150 for prior discussion
    on this subject (with the proposed keyword being ``given:``).
 
+5. ``TARGET from EXPR``::
+
+       stuff = [[y from f(x), x/y] for x in range(5)]
+
+   This syntax has fewer conflicts than ``as`` does (conflicting only with the
+   ``raise Exc from Exc`` notation), but is otherwise comparable to it. Instead
+   of paralleling ``with expr as target:`` (which can be useful but can also be
+   confusing), this has no parallels, but is evocative.
+
 
 Special-casing conditional statements
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