| Step | Hyp | Ref | Expression | 
						
							| 1 |  | rexpen | ⊢ ( ℝ  ×  ℝ )  ≈  ℝ | 
						
							| 2 |  | eleq1w | ⊢ ( 𝑣  =  𝑥  →  ( 𝑣  ∈  ℝ  ↔  𝑥  ∈  ℝ ) ) | 
						
							| 3 |  | eleq1w | ⊢ ( 𝑤  =  𝑦  →  ( 𝑤  ∈  ℝ  ↔  𝑦  ∈  ℝ ) ) | 
						
							| 4 | 2 3 | bi2anan9 | ⊢ ( ( 𝑣  =  𝑥  ∧  𝑤  =  𝑦 )  →  ( ( 𝑣  ∈  ℝ  ∧  𝑤  ∈  ℝ )  ↔  ( 𝑥  ∈  ℝ  ∧  𝑦  ∈  ℝ ) ) ) | 
						
							| 5 |  | oveq2 | ⊢ ( 𝑤  =  𝑦  →  ( i  ·  𝑤 )  =  ( i  ·  𝑦 ) ) | 
						
							| 6 |  | oveq12 | ⊢ ( ( 𝑣  =  𝑥  ∧  ( i  ·  𝑤 )  =  ( i  ·  𝑦 ) )  →  ( 𝑣  +  ( i  ·  𝑤 ) )  =  ( 𝑥  +  ( i  ·  𝑦 ) ) ) | 
						
							| 7 | 5 6 | sylan2 | ⊢ ( ( 𝑣  =  𝑥  ∧  𝑤  =  𝑦 )  →  ( 𝑣  +  ( i  ·  𝑤 ) )  =  ( 𝑥  +  ( i  ·  𝑦 ) ) ) | 
						
							| 8 | 7 | eqeq2d | ⊢ ( ( 𝑣  =  𝑥  ∧  𝑤  =  𝑦 )  →  ( 𝑧  =  ( 𝑣  +  ( i  ·  𝑤 ) )  ↔  𝑧  =  ( 𝑥  +  ( i  ·  𝑦 ) ) ) ) | 
						
							| 9 | 4 8 | anbi12d | ⊢ ( ( 𝑣  =  𝑥  ∧  𝑤  =  𝑦 )  →  ( ( ( 𝑣  ∈  ℝ  ∧  𝑤  ∈  ℝ )  ∧  𝑧  =  ( 𝑣  +  ( i  ·  𝑤 ) ) )  ↔  ( ( 𝑥  ∈  ℝ  ∧  𝑦  ∈  ℝ )  ∧  𝑧  =  ( 𝑥  +  ( i  ·  𝑦 ) ) ) ) ) | 
						
							| 10 | 9 | cbvoprab12v | ⊢ { 〈 〈 𝑣 ,  𝑤 〉 ,  𝑧 〉  ∣  ( ( 𝑣  ∈  ℝ  ∧  𝑤  ∈  ℝ )  ∧  𝑧  =  ( 𝑣  +  ( i  ·  𝑤 ) ) ) }  =  { 〈 〈 𝑥 ,  𝑦 〉 ,  𝑧 〉  ∣  ( ( 𝑥  ∈  ℝ  ∧  𝑦  ∈  ℝ )  ∧  𝑧  =  ( 𝑥  +  ( i  ·  𝑦 ) ) ) } | 
						
							| 11 |  | df-mpo | ⊢ ( 𝑥  ∈  ℝ ,  𝑦  ∈  ℝ  ↦  ( 𝑥  +  ( i  ·  𝑦 ) ) )  =  { 〈 〈 𝑥 ,  𝑦 〉 ,  𝑧 〉  ∣  ( ( 𝑥  ∈  ℝ  ∧  𝑦  ∈  ℝ )  ∧  𝑧  =  ( 𝑥  +  ( i  ·  𝑦 ) ) ) } | 
						
							| 12 | 10 11 | eqtr4i | ⊢ { 〈 〈 𝑣 ,  𝑤 〉 ,  𝑧 〉  ∣  ( ( 𝑣  ∈  ℝ  ∧  𝑤  ∈  ℝ )  ∧  𝑧  =  ( 𝑣  +  ( i  ·  𝑤 ) ) ) }  =  ( 𝑥  ∈  ℝ ,  𝑦  ∈  ℝ  ↦  ( 𝑥  +  ( i  ·  𝑦 ) ) ) | 
						
							| 13 | 12 | cnref1o | ⊢ { 〈 〈 𝑣 ,  𝑤 〉 ,  𝑧 〉  ∣  ( ( 𝑣  ∈  ℝ  ∧  𝑤  ∈  ℝ )  ∧  𝑧  =  ( 𝑣  +  ( i  ·  𝑤 ) ) ) } : ( ℝ  ×  ℝ ) –1-1-onto→ ℂ | 
						
							| 14 |  | reex | ⊢ ℝ  ∈  V | 
						
							| 15 | 14 14 | xpex | ⊢ ( ℝ  ×  ℝ )  ∈  V | 
						
							| 16 | 15 | f1oen | ⊢ ( { 〈 〈 𝑣 ,  𝑤 〉 ,  𝑧 〉  ∣  ( ( 𝑣  ∈  ℝ  ∧  𝑤  ∈  ℝ )  ∧  𝑧  =  ( 𝑣  +  ( i  ·  𝑤 ) ) ) } : ( ℝ  ×  ℝ ) –1-1-onto→ ℂ  →  ( ℝ  ×  ℝ )  ≈  ℂ ) | 
						
							| 17 | 13 16 | ax-mp | ⊢ ( ℝ  ×  ℝ )  ≈  ℂ | 
						
							| 18 | 1 17 | entr3i | ⊢ ℝ  ≈  ℂ | 
						
							| 19 |  | rpnnen | ⊢ ℝ  ≈  𝒫  ℕ | 
						
							| 20 | 18 19 | entr3i | ⊢ ℂ  ≈  𝒫  ℕ |