Metamath Proof Explorer
		
		
		
		Description:  The group addition operation of R is the addition of complex numbers.
       (Contributed by AV, 31-Jan-2020)
		
			
				
					|  |  | Ref | Expression | 
					
						|  | Hypotheses | 2zrng.e | ⊢ 𝐸  =  { 𝑧  ∈  ℤ  ∣  ∃ 𝑥  ∈  ℤ 𝑧  =  ( 2  ·  𝑥 ) } | 
					
						|  |  | 2zrngbas.r | ⊢ 𝑅  =  ( ℂfld  ↾s  𝐸 ) | 
				
					|  | Assertion | 2zrngadd | ⊢   +   =  ( +g ‘ 𝑅 ) | 
			
		
		
			
				Proof
				
					
						| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 2zrng.e | ⊢ 𝐸  =  { 𝑧  ∈  ℤ  ∣  ∃ 𝑥  ∈  ℤ 𝑧  =  ( 2  ·  𝑥 ) } | 
						
							| 2 |  | 2zrngbas.r | ⊢ 𝑅  =  ( ℂfld  ↾s  𝐸 ) | 
						
							| 3 |  | zex | ⊢ ℤ  ∈  V | 
						
							| 4 | 1 3 | rabex2 | ⊢ 𝐸  ∈  V | 
						
							| 5 | 2 | cnfldsrngadd | ⊢ ( 𝐸  ∈  V  →   +   =  ( +g ‘ 𝑅 ) ) | 
						
							| 6 | 4 5 | ax-mp | ⊢  +   =  ( +g ‘ 𝑅 ) |