Theorem seqeq2

Description: Equality theorem for the sequence builder operation. (Contributed by Mario Carneiro, 4-Sep-2013)

	Ref	Expression
Assertion	seqeq2	⊢ ( + = 𝑄 → seq 𝑀 ( + , 𝐹 ) = seq 𝑀 ( 𝑄 , 𝐹 ) )

Proof

Step	Hyp	Ref	Expression
1		oveq	⊢ ( + = 𝑄 → ( 𝑦 + ( 𝐹 ‘ ( 𝑥 + 1 ) ) ) = ( 𝑦 𝑄 ( 𝐹 ‘ ( 𝑥 + 1 ) ) ) )
2	1	opeq2d	⊢ ( + = 𝑄 → ⟨ ( 𝑥 + 1 ) , ( 𝑦 + ( 𝐹 ‘ ( 𝑥 + 1 ) ) ) ⟩ = ⟨ ( 𝑥 + 1 ) , ( 𝑦 𝑄 ( 𝐹 ‘ ( 𝑥 + 1 ) ) ) ⟩ )
3	2	mpoeq3dv	⊢ ( + = 𝑄 → ( 𝑥 ∈ V , 𝑦 ∈ V ↦ ⟨ ( 𝑥 + 1 ) , ( 𝑦 + ( 𝐹 ‘ ( 𝑥 + 1 ) ) ) ⟩ ) = ( 𝑥 ∈ V , 𝑦 ∈ V ↦ ⟨ ( 𝑥 + 1 ) , ( 𝑦 𝑄 ( 𝐹 ‘ ( 𝑥 + 1 ) ) ) ⟩ ) )
4		rdgeq1	⊢ ( ( 𝑥 ∈ V , 𝑦 ∈ V ↦ ⟨ ( 𝑥 + 1 ) , ( 𝑦 + ( 𝐹 ‘ ( 𝑥 + 1 ) ) ) ⟩ ) = ( 𝑥 ∈ V , 𝑦 ∈ V ↦ ⟨ ( 𝑥 + 1 ) , ( 𝑦 𝑄 ( 𝐹 ‘ ( 𝑥 + 1 ) ) ) ⟩ ) → rec ( ( 𝑥 ∈ V , 𝑦 ∈ V ↦ ⟨ ( 𝑥 + 1 ) , ( 𝑦 + ( 𝐹 ‘ ( 𝑥 + 1 ) ) ) ⟩ ) , ⟨ 𝑀 , ( 𝐹 ‘ 𝑀 ) ⟩ ) = rec ( ( 𝑥 ∈ V , 𝑦 ∈ V ↦ ⟨ ( 𝑥 + 1 ) , ( 𝑦 𝑄 ( 𝐹 ‘ ( 𝑥 + 1 ) ) ) ⟩ ) , ⟨ 𝑀 , ( 𝐹 ‘ 𝑀 ) ⟩ ) )
5	3 4	syl	⊢ ( + = 𝑄 → rec ( ( 𝑥 ∈ V , 𝑦 ∈ V ↦ ⟨ ( 𝑥 + 1 ) , ( 𝑦 + ( 𝐹 ‘ ( 𝑥 + 1 ) ) ) ⟩ ) , ⟨ 𝑀 , ( 𝐹 ‘ 𝑀 ) ⟩ ) = rec ( ( 𝑥 ∈ V , 𝑦 ∈ V ↦ ⟨ ( 𝑥 + 1 ) , ( 𝑦 𝑄 ( 𝐹 ‘ ( 𝑥 + 1 ) ) ) ⟩ ) , ⟨ 𝑀 , ( 𝐹 ‘ 𝑀 ) ⟩ ) )
6	5	imaeq1d	⊢ ( + = 𝑄 → ( rec ( ( 𝑥 ∈ V , 𝑦 ∈ V ↦ ⟨ ( 𝑥 + 1 ) , ( 𝑦 + ( 𝐹 ‘ ( 𝑥 + 1 ) ) ) ⟩ ) , ⟨ 𝑀 , ( 𝐹 ‘ 𝑀 ) ⟩ ) “ ω ) = ( rec ( ( 𝑥 ∈ V , 𝑦 ∈ V ↦ ⟨ ( 𝑥 + 1 ) , ( 𝑦 𝑄 ( 𝐹 ‘ ( 𝑥 + 1 ) ) ) ⟩ ) , ⟨ 𝑀 , ( 𝐹 ‘ 𝑀 ) ⟩ ) “ ω ) )
7		df-seq	⊢ seq 𝑀 ( + , 𝐹 ) = ( rec ( ( 𝑥 ∈ V , 𝑦 ∈ V ↦ ⟨ ( 𝑥 + 1 ) , ( 𝑦 + ( 𝐹 ‘ ( 𝑥 + 1 ) ) ) ⟩ ) , ⟨ 𝑀 , ( 𝐹 ‘ 𝑀 ) ⟩ ) “ ω )
8		df-seq	⊢ seq 𝑀 ( 𝑄 , 𝐹 ) = ( rec ( ( 𝑥 ∈ V , 𝑦 ∈ V ↦ ⟨ ( 𝑥 + 1 ) , ( 𝑦 𝑄 ( 𝐹 ‘ ( 𝑥 + 1 ) ) ) ⟩ ) , ⟨ 𝑀 , ( 𝐹 ‘ 𝑀 ) ⟩ ) “ ω )
9	6 7 8	3eqtr4g	⊢ ( + = 𝑄 → seq 𝑀 ( + , 𝐹 ) = seq 𝑀 ( 𝑄 , 𝐹 ) )