An injective map between two sets of the same cardinality is bijective if at least one of the sets is finite. This is not true if we drop the assumption that at least one of the sets is finite. Is there a strengthening of the notion of injectivity such that the statement continues to hold?
closed as off-topic by YCor, Yoav Kallus, Jeremy Rickard, LSpice, Yemon Choi Jul 3 at 1:17
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