Proposition: Prop. 9.25: Even Number minus Odd Number is Odd
(Proposition 25 from Book 9 of Euclid's “Elements”)
If an odd (number) is subtracted from an even number then the remainder will be odd.
 For let the odd (number) $BC$ have been subtracted from the even number $AB$.
 I say that the remainder $CA$ is odd.
Modern Formulation
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Table of Contents
Proofs: 1
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References
Adapted from (subject to copyright, with kind permission)
 Fitzpatrick, Richard: Euclid's "Elements of Geometry"
Adapted from CC BYSA 3.0 Sources:
 Prime.mover and others: "Pr∞fWiki", https://proofwiki.org/wiki/Main_Page, 2016