Metamath Proof Explorer


Definition df-wsuc

Description: Define the concept of a successor in a well-founded set. (Contributed by Scott Fenton, 13-Jun-2018) (Revised by AV, 10-Oct-2021)

Ref Expression
Assertion df-wsuc wsuc R A X = sup Pred R -1 A X A R

Detailed syntax breakdown

Step Hyp Ref Expression
0 cR class R
1 cA class A
2 cX class X
3 1 0 2 cwsuc class wsuc R A X
4 0 ccnv class R -1
5 1 4 2 cpred class Pred R -1 A X
6 5 1 0 cinf class sup Pred R -1 A X A R
7 3 6 wceq wff wsuc R A X = sup Pred R -1 A X A R