Metamath Proof Explorer


Theorem isf32lem3

Description: Lemma for isfin3-2 . Being a chain, difference sets are disjoint (one case). (Contributed by Stefan O'Rear, 5-Nov-2014)

Ref Expression
Hypotheses isf32lem.a φ F : ω 𝒫 G
isf32lem.b φ x ω F suc x F x
isf32lem.c φ ¬ ran F ran F
Assertion isf32lem3 A ω B ω B A φ F A F suc A F B F suc B =

Proof

Step Hyp Ref Expression
1 isf32lem.a φ F : ω 𝒫 G
2 isf32lem.b φ x ω F suc x F x
3 isf32lem.c φ ¬ ran F ran F
4 eldifi a F A F suc A a F A
5 simpll A ω B ω B A φ A ω
6 peano2 B ω suc B ω
7 6 ad2antlr A ω B ω B A φ suc B ω
8 nnord A ω Ord A
9 8 ad2antrr A ω B ω B A φ Ord A
10 simprl A ω B ω B A φ B A
11 ordsucss Ord A B A suc B A
12 9 10 11 sylc A ω B ω B A φ suc B A
13 simprr A ω B ω B A φ φ
14 1 2 3 isf32lem1 A ω suc B ω suc B A φ F A F suc B
15 5 7 12 13 14 syl22anc A ω B ω B A φ F A F suc B
16 15 sseld A ω B ω B A φ a F A a F suc B
17 elndif a F suc B ¬ a F B F suc B
18 4 16 17 syl56 A ω B ω B A φ a F A F suc A ¬ a F B F suc B
19 18 ralrimiv A ω B ω B A φ a F A F suc A ¬ a F B F suc B
20 disj F A F suc A F B F suc B = a F A F suc A ¬ a F B F suc B
21 19 20 sylibr A ω B ω B A φ F A F suc A F B F suc B =