Metamath Proof Explorer


Theorem dffr5

Description: A quantifier-free definition of a well-founded relationship. (Contributed by Scott Fenton, 11-Apr-2011)

Ref Expression
Assertion dffr5 RFrA𝒫AranEER-1

Proof

Step Hyp Ref Expression
1 eldif x𝒫Ax𝒫A¬x
2 velpw x𝒫AxA
3 velsn xx=
4 3 necon3bbii ¬xx
5 2 4 anbi12i x𝒫A¬xxAx
6 1 5 bitri x𝒫AxAx
7 brdif yEER-1xyEx¬yER-1x
8 epel yExyx
9 vex yV
10 vex xV
11 9 10 coep yER-1xzxyR-1z
12 vex zV
13 9 12 brcnv yR-1zzRy
14 13 rexbii zxyR-1zzxzRy
15 dfrex2 zxzRy¬zx¬zRy
16 11 14 15 3bitrri ¬zx¬zRyyER-1x
17 16 con1bii ¬yER-1xzx¬zRy
18 8 17 anbi12i yEx¬yER-1xyxzx¬zRy
19 7 18 bitri yEER-1xyxzx¬zRy
20 19 exbii yyEER-1xyyxzx¬zRy
21 10 elrn xranEER-1yyEER-1x
22 df-rex yxzx¬zRyyyxzx¬zRy
23 20 21 22 3bitr4i xranEER-1yxzx¬zRy
24 6 23 imbi12i x𝒫AxranEER-1xAxyxzx¬zRy
25 24 albii xx𝒫AxranEER-1xxAxyxzx¬zRy
26 dfss2 𝒫AranEER-1xx𝒫AxranEER-1
27 df-fr RFrAxxAxyxzx¬zRy
28 25 26 27 3bitr4ri RFrA𝒫AranEER-1