Theorem oppraddOLD

Description: Obsolete proof of opprbas as of 6-Nov-2024. Addition operation of an opposite ring. (Contributed by Mario Carneiro, 1-Dec-2014) (New usage is discouraged.) (Proof modification is discouraged.)

	Ref	Expression
Hypotheses	opprbas.1	⊢ 𝑂 = ( oppr ‘ 𝑅 )
	oppradd.2	⊢ + = ( +g ‘ 𝑅 )
Assertion	oppraddOLD	⊢ + = ( +g ‘ 𝑂 )

Proof

Step	Hyp	Ref	Expression
1		opprbas.1	⊢ 𝑂 = ( oppr ‘ 𝑅 )
2		oppradd.2	⊢ + = ( +g ‘ 𝑅 )
3		df-plusg	⊢ +g = Slot 2
4		2nn	⊢ 2 ∈ ℕ
5		2lt3	⊢ 2 < 3
6	1 3 4 5	opprlemOLD	⊢ ( +g ‘ 𝑅 ) = ( +g ‘ 𝑂 )
7	2 6	eqtri	⊢ + = ( +g ‘ 𝑂 )