Did Zorn know this when he wrote his 1935 paper? Well at the end of the 1935 paper he did say that these three are all equivalent and promised a proof in a future paper. Was Zorn's idea entirely new? Well similar maximum principles had been proposed earlier in different contexts by several mathematicians, for example Hausdorff, Kuratowski and Brouwer . Paul Campbell examines this question in and:
Malalaman Zorn ba ito kapag siya wrote kanyang 1935 papel? Well sa katapusan ng 1935 na papel siya ay sinasabi na ang mga ito ay ang lahat ng tatlong mga katumbas at ipinangako isang patunay sa isang hinaharap na papel. Zorn's ideya ay ganap na bagong? Well katulad na pinakamataas na prinsipyo had been iminungkahing mas maaga sa iba't-ibang konteksto sa pamamagitan ng ilang mga mathematicians, para sa mga halimbawa Hausdorff, Kuratowski at Brouwer. Paul Campbell ang tanong na ito sa at: