Given a set $X$, can you always find a disjoint set $Y$ such that there is a bijection between them? This is easy with AC. you can well order X and replace each $x\in X$ with the least ordinal not already in $X$. I am unsure how to proceed without AC though.
2026-04-07 21:47:18.1775598438
Creating an equinumerous disjoint set without axiom of choice
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