Metamath Proof Explorer


Theorem isfin32i

Description: One half of isfin3-2 . (Contributed by Mario Carneiro, 3-Jun-2015)

Ref Expression
Assertion isfin32i A FinIII ¬ ω * A

Proof

Step Hyp Ref Expression
1 isfin3 A FinIII 𝒫 A FinIV
2 isfin4-2 𝒫 A FinIV 𝒫 A FinIV ¬ ω 𝒫 A
3 2 ibi 𝒫 A FinIV ¬ ω 𝒫 A
4 relwdom Rel *
5 4 brrelex1i ω * A ω V
6 canth2g ω V ω 𝒫 ω
7 sdomdom ω 𝒫 ω ω 𝒫 ω
8 5 6 7 3syl ω * A ω 𝒫 ω
9 wdompwdom ω * A 𝒫 ω 𝒫 A
10 domtr ω 𝒫 ω 𝒫 ω 𝒫 A ω 𝒫 A
11 8 9 10 syl2anc ω * A ω 𝒫 A
12 3 11 nsyl 𝒫 A FinIV ¬ ω * A
13 1 12 sylbi A FinIII ¬ ω * A