| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cnfldbas | ⊢ ℂ  =  ( Base ‘ ℂfld ) | 
						
							| 2 | 1 | a1i | ⊢ ( ⊤  →  ℂ  =  ( Base ‘ ℂfld ) ) | 
						
							| 3 |  | cnfldadd | ⊢  +   =  ( +g ‘ ℂfld ) | 
						
							| 4 | 3 | a1i | ⊢ ( ⊤  →   +   =  ( +g ‘ ℂfld ) ) | 
						
							| 5 |  | cnfldmul | ⊢  ·   =  ( .r ‘ ℂfld ) | 
						
							| 6 | 5 | a1i | ⊢ ( ⊤  →   ·   =  ( .r ‘ ℂfld ) ) | 
						
							| 7 |  | addcl | ⊢ ( ( 𝑥  ∈  ℂ  ∧  𝑦  ∈  ℂ )  →  ( 𝑥  +  𝑦 )  ∈  ℂ ) | 
						
							| 8 |  | addass | ⊢ ( ( 𝑥  ∈  ℂ  ∧  𝑦  ∈  ℂ  ∧  𝑧  ∈  ℂ )  →  ( ( 𝑥  +  𝑦 )  +  𝑧 )  =  ( 𝑥  +  ( 𝑦  +  𝑧 ) ) ) | 
						
							| 9 |  | 0cn | ⊢ 0  ∈  ℂ | 
						
							| 10 |  | addlid | ⊢ ( 𝑥  ∈  ℂ  →  ( 0  +  𝑥 )  =  𝑥 ) | 
						
							| 11 |  | negcl | ⊢ ( 𝑥  ∈  ℂ  →  - 𝑥  ∈  ℂ ) | 
						
							| 12 |  | addcom | ⊢ ( ( - 𝑥  ∈  ℂ  ∧  𝑥  ∈  ℂ )  →  ( - 𝑥  +  𝑥 )  =  ( 𝑥  +  - 𝑥 ) ) | 
						
							| 13 | 11 12 | mpancom | ⊢ ( 𝑥  ∈  ℂ  →  ( - 𝑥  +  𝑥 )  =  ( 𝑥  +  - 𝑥 ) ) | 
						
							| 14 |  | negid | ⊢ ( 𝑥  ∈  ℂ  →  ( 𝑥  +  - 𝑥 )  =  0 ) | 
						
							| 15 | 13 14 | eqtrd | ⊢ ( 𝑥  ∈  ℂ  →  ( - 𝑥  +  𝑥 )  =  0 ) | 
						
							| 16 | 1 3 7 8 9 10 11 15 | isgrpi | ⊢ ℂfld  ∈  Grp | 
						
							| 17 | 16 | a1i | ⊢ ( ⊤  →  ℂfld  ∈  Grp ) | 
						
							| 18 |  | mulcl | ⊢ ( ( 𝑥  ∈  ℂ  ∧  𝑦  ∈  ℂ )  →  ( 𝑥  ·  𝑦 )  ∈  ℂ ) | 
						
							| 19 | 18 | 3adant1 | ⊢ ( ( ⊤  ∧  𝑥  ∈  ℂ  ∧  𝑦  ∈  ℂ )  →  ( 𝑥  ·  𝑦 )  ∈  ℂ ) | 
						
							| 20 |  | mulass | ⊢ ( ( 𝑥  ∈  ℂ  ∧  𝑦  ∈  ℂ  ∧  𝑧  ∈  ℂ )  →  ( ( 𝑥  ·  𝑦 )  ·  𝑧 )  =  ( 𝑥  ·  ( 𝑦  ·  𝑧 ) ) ) | 
						
							| 21 | 20 | adantl | ⊢ ( ( ⊤  ∧  ( 𝑥  ∈  ℂ  ∧  𝑦  ∈  ℂ  ∧  𝑧  ∈  ℂ ) )  →  ( ( 𝑥  ·  𝑦 )  ·  𝑧 )  =  ( 𝑥  ·  ( 𝑦  ·  𝑧 ) ) ) | 
						
							| 22 |  | adddi | ⊢ ( ( 𝑥  ∈  ℂ  ∧  𝑦  ∈  ℂ  ∧  𝑧  ∈  ℂ )  →  ( 𝑥  ·  ( 𝑦  +  𝑧 ) )  =  ( ( 𝑥  ·  𝑦 )  +  ( 𝑥  ·  𝑧 ) ) ) | 
						
							| 23 | 22 | adantl | ⊢ ( ( ⊤  ∧  ( 𝑥  ∈  ℂ  ∧  𝑦  ∈  ℂ  ∧  𝑧  ∈  ℂ ) )  →  ( 𝑥  ·  ( 𝑦  +  𝑧 ) )  =  ( ( 𝑥  ·  𝑦 )  +  ( 𝑥  ·  𝑧 ) ) ) | 
						
							| 24 |  | adddir | ⊢ ( ( 𝑥  ∈  ℂ  ∧  𝑦  ∈  ℂ  ∧  𝑧  ∈  ℂ )  →  ( ( 𝑥  +  𝑦 )  ·  𝑧 )  =  ( ( 𝑥  ·  𝑧 )  +  ( 𝑦  ·  𝑧 ) ) ) | 
						
							| 25 | 24 | adantl | ⊢ ( ( ⊤  ∧  ( 𝑥  ∈  ℂ  ∧  𝑦  ∈  ℂ  ∧  𝑧  ∈  ℂ ) )  →  ( ( 𝑥  +  𝑦 )  ·  𝑧 )  =  ( ( 𝑥  ·  𝑧 )  +  ( 𝑦  ·  𝑧 ) ) ) | 
						
							| 26 |  | 1cnd | ⊢ ( ⊤  →  1  ∈  ℂ ) | 
						
							| 27 |  | mullid | ⊢ ( 𝑥  ∈  ℂ  →  ( 1  ·  𝑥 )  =  𝑥 ) | 
						
							| 28 | 27 | adantl | ⊢ ( ( ⊤  ∧  𝑥  ∈  ℂ )  →  ( 1  ·  𝑥 )  =  𝑥 ) | 
						
							| 29 |  | mulrid | ⊢ ( 𝑥  ∈  ℂ  →  ( 𝑥  ·  1 )  =  𝑥 ) | 
						
							| 30 | 29 | adantl | ⊢ ( ( ⊤  ∧  𝑥  ∈  ℂ )  →  ( 𝑥  ·  1 )  =  𝑥 ) | 
						
							| 31 |  | mulcom | ⊢ ( ( 𝑥  ∈  ℂ  ∧  𝑦  ∈  ℂ )  →  ( 𝑥  ·  𝑦 )  =  ( 𝑦  ·  𝑥 ) ) | 
						
							| 32 | 31 | 3adant1 | ⊢ ( ( ⊤  ∧  𝑥  ∈  ℂ  ∧  𝑦  ∈  ℂ )  →  ( 𝑥  ·  𝑦 )  =  ( 𝑦  ·  𝑥 ) ) | 
						
							| 33 | 2 4 6 17 19 21 23 25 26 28 30 32 | iscrngd | ⊢ ( ⊤  →  ℂfld  ∈  CRing ) | 
						
							| 34 | 33 | mptru | ⊢ ℂfld  ∈  CRing |