On Wed, May 4, 2016 at 11:19 AM Guido van Rossum <guido@python.org> wrote:

- In ABC, this was considered, and the rule was that {k1: v1; k2: v2} was allowed to have k1==k2 as long as v1==v2. Otherwise it was an error. (But ABC did not have comprehensions.)

Was that enforced by comparing the expressions or the resulting values?