Metamath Proof Explorer


Theorem wfr2OLD

Description: Obsolete proof of wfr2 as of 18-Nov-2024. (New usage is discouraged.) (Proof modification is discouraged.) (Contributed by Scott Fenton, 18-Apr-2011) (Revised by Mario Carneiro, 26-Jun-2015)

Ref Expression
Hypotheses wfr2OLD.1 𝑅 We 𝐴
wfr2OLD.2 𝑅 Se 𝐴
wfr2OLD.3 𝐹 = wrecs ( 𝑅 , 𝐴 , 𝐺 )
Assertion wfr2OLD ( 𝑋𝐴 → ( 𝐹𝑋 ) = ( 𝐺 ‘ ( 𝐹 ↾ Pred ( 𝑅 , 𝐴 , 𝑋 ) ) ) )

Proof

Step Hyp Ref Expression
1 wfr2OLD.1 𝑅 We 𝐴
2 wfr2OLD.2 𝑅 Se 𝐴
3 wfr2OLD.3 𝐹 = wrecs ( 𝑅 , 𝐴 , 𝐺 )
4 eqid ( 𝐹 ∪ { ⟨ 𝑥 , ( 𝐺 ‘ ( 𝐹 ↾ Pred ( 𝑅 , 𝐴 , 𝑥 ) ) ) ⟩ } ) = ( 𝐹 ∪ { ⟨ 𝑥 , ( 𝐺 ‘ ( 𝐹 ↾ Pred ( 𝑅 , 𝐴 , 𝑥 ) ) ) ⟩ } )
5 1 2 3 4 wfrlem16OLD dom 𝐹 = 𝐴
6 5 eleq2i ( 𝑋 ∈ dom 𝐹𝑋𝐴 )
7 1 2 3 wfr2aOLD ( 𝑋 ∈ dom 𝐹 → ( 𝐹𝑋 ) = ( 𝐺 ‘ ( 𝐹 ↾ Pred ( 𝑅 , 𝐴 , 𝑋 ) ) ) )
8 6 7 sylbir ( 𝑋𝐴 → ( 𝐹𝑋 ) = ( 𝐺 ‘ ( 𝐹 ↾ Pred ( 𝑅 , 𝐴 , 𝑋 ) ) ) )