13-1a3a1 The essence of the exchange is that both people make it because they expect that it will benefit them

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• 13-1a3a2 A necessary condition for an exchange to take place is that the two goods have reverse valuations on the respective value scales of the two parties to the exchange

Related:

• 5-3a Knowledge via new explanations is inherently creative and its effects are positive-sum, because it begets new problems to be solved
• 13-6a1 Without knowledge, self-identity is no stronger than the identity between any two people
• 13-6c1 The action axiom meaningfully implies corresponding value scales only when the action is mediated via corresponding knowledge
• 13-1b The mind, with its intention, can shape the multiverse