        or permissible update to the knowledge base).

   "A =df B" is a statement that A and B are equal by definition
           not only for the current state of affairs, but for any
           permissible or accessible state.

Now that we agree on this point, I would like to have a suitable
notation in KIF, such as "def", for asserting that some statement of
equality or equivalence is by definition rather than by happenstance.

John Sowa
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