Ideas from 'works' by Ernst Zermelo [1920], by Theme Structure

Click on the Idea Number for the full details    |     back to texts     |     expand these ideas

4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
For Zermelo's set theory the empty set is zero and the successor of each number is its unit set
Zermelo made 'set' and 'member' undefined axioms