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Topic: Natural numbers embedded in other sets
Replies: 1   Last Post: Mar 14, 2013 10:08 AM

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Dan Christensen

Posts: 8,219
Registered: 7/9/08
Natural numbers embedded in other sets
Posted: Feb 13, 2013 6:13 PM
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Here is a formal proof (112 lines in DC Proof format), that proves the existence of natural number-like structures in every set S on which there is (1) a one-to-one (injective) mapping f, and (2) at least one element that has no pre-image under f.

Download my DC Proof 2.0 freeware at:
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