Proposition: Prop. 9.31: Odd Number Co-prime to Number is also Co-prime to its Double

Euclid's Formulation

If an odd number is prime to some number then it will also be prime to its double. * For let the odd number $A$ be prime to some number $B$. * And let $C$ be double $B$. * I say that $A$ is [also] [prime to]bookofproofs$1288 $C$.

fig31e

Modern Formulation

(not yet contributed)

Proofs: 1


Thank you to the contributors under CC BY-SA 4.0!

Github:
bookofproofs
non-Github:
@Fitzpatrick


References

Adapted from (subject to copyright, with kind permission)

  1. Fitzpatrick, Richard: Euclid's "Elements of Geometry"

Adapted from CC BY-SA 3.0 Sources:

  1. Prime.mover and others: "Pr∞fWiki", https://proofwiki.org/wiki/Main_Page, 2016