Description: Given any function F from well-orderings of subsets of A to A , there is a unique well-ordered subset <. X , ( WX ) >. which "agrees" with F in the sense that each initial segment maps to its upper bound, and such that the entire set maps to an element of the set (so that it cannot be extended without losing the well-ordering). This theorem can be used to prove dfac8a . Theorem 1.1 of KanamoriPincus p. 415. (Contributed by Mario Carneiro, 18-May-2015) (Revised by AV, 20-Jul-2024)
Ref | Expression | ||
---|---|---|---|
Hypotheses | fpwwe2.1 | |
|
fpwwe2.2 | |
||
fpwwe2.3 | |
||
fpwwe2.4 | |
||
Assertion | fpwwe2 | |