Metamath Proof Explorer


Theorem fin23lem20

Description: Lemma for fin23 . X is either contained in or disjoint from all input sets. (Contributed by Stefan O'Rear, 1-Nov-2014)

Ref Expression
Hypothesis fin23lem.a U=seqωiω,uViftiu=utiurant
Assertion fin23lem20 AωranUtAranUtA=

Proof

Step Hyp Ref Expression
1 fin23lem.a U=seqωiω,uViftiu=utiurant
2 1 fnseqom UFnω
3 peano2 AωsucAω
4 fnfvelrn UFnωsucAωUsucAranU
5 2 3 4 sylancr AωUsucAranU
6 intss1 UsucAranUranUUsucA
7 5 6 syl AωranUUsucA
8 1 fin23lem19 AωUsucAtAUsucAtA=
9 sstr2 ranUUsucAUsucAtAranUtA
10 ssdisj ranUUsucAUsucAtA=ranUtA=
11 10 ex ranUUsucAUsucAtA=ranUtA=
12 9 11 orim12d ranUUsucAUsucAtAUsucAtA=ranUtAranUtA=
13 7 8 12 sylc AωranUtAranUtA=