Can a function $f:A\to A$ be onto but not injective? My thought process would be that if it is onto, then the $range(f)$ would be $A$. Then wouldn't it follow that the function is one-to-one, since $|dom(f)| = |range(f)|$.
2026-04-22 21:42:21.1776894141
Relationship between Bijections and Cardinality
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