Metamath Proof Explorer


Theorem frrlem16

Description: Lemma for general well-founded recursion. Establish a subset relation. (Contributed by Scott Fenton, 11-Sep-2023) Revised notion of transitive closure. (Revised by Scott Fenton, 1-Dec-2024)

Ref Expression
Assertion frrlem16 R Fr A R Se A z A w Pred t++ R A A z Pred R A w Pred t++ R A A z

Proof

Step Hyp Ref Expression
1 predres Pred R A w = Pred R A A w
2 relres Rel R A
3 ssttrcl Rel R A R A t++ R A
4 2 3 ax-mp R A t++ R A
5 predrelss R A t++ R A Pred R A A w Pred t++ R A A w
6 4 5 ax-mp Pred R A A w Pred t++ R A A w
7 1 6 eqsstri Pred R A w Pred t++ R A A w
8 inss1 t++ R A A × A t++ R A
9 coss1 t++ R A A × A t++ R A t++ R A A × A t++ R A A × A t++ R A t++ R A A × A
10 8 9 ax-mp t++ R A A × A t++ R A A × A t++ R A t++ R A A × A
11 coss2 t++ R A A × A t++ R A t++ R A t++ R A A × A t++ R A t++ R A
12 8 11 ax-mp t++ R A t++ R A A × A t++ R A t++ R A
13 10 12 sstri t++ R A A × A t++ R A A × A t++ R A t++ R A
14 ttrcltr t++ R A t++ R A t++ R A
15 13 14 sstri t++ R A A × A t++ R A A × A t++ R A
16 predtrss t++ R A A × A t++ R A A × A t++ R A w Pred t++ R A A z z A Pred t++ R A A w Pred t++ R A A z
17 15 16 mp3an1 w Pred t++ R A A z z A Pred t++ R A A w Pred t++ R A A z
18 7 17 sstrid w Pred t++ R A A z z A Pred R A w Pred t++ R A A z
19 18 ancoms z A w Pred t++ R A A z Pred R A w Pred t++ R A A z
20 19 ralrimiva z A w Pred t++ R A A z Pred R A w Pred t++ R A A z
21 20 adantl R Fr A R Se A z A w Pred t++ R A A z Pred R A w Pred t++ R A A z