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Revision difference : pigeonhole principle |
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Version 4 |
| For any natural number $n$, there does not exist a bijection between $n$ and a proper subset of $n$. |
For any natural number $n$, there does not exist a bijection between $n$ and a proper subset of $n$. |
| The name of the theorem is based upon the observation that pigeons will not occupy a pigeonhole that already contains a pigeon, so there is no way to fit $n$ pigeons in fewer than $n$ pigeonholes. |
The name of the theorem is based upon the observation that pigeons will not occupy a pigeonhole that already contains a pigeon, so there is no way to fit $n$ pigeons in fewer than $n$ pigeonholes. |
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