| Step | Hyp | Ref | Expression | 
						
							| 1 |  | tskmval | ⊢ ( 𝐴  ∈  𝑉  →  ( tarskiMap ‘ 𝐴 )  =  ∩  { 𝑥  ∈  Tarski  ∣  𝐴  ∈  𝑥 } ) | 
						
							| 2 | 1 | eleq2d | ⊢ ( 𝐴  ∈  𝑉  →  ( 𝐵  ∈  ( tarskiMap ‘ 𝐴 )  ↔  𝐵  ∈  ∩  { 𝑥  ∈  Tarski  ∣  𝐴  ∈  𝑥 } ) ) | 
						
							| 3 |  | elex | ⊢ ( 𝐵  ∈  ∩  { 𝑥  ∈  Tarski  ∣  𝐴  ∈  𝑥 }  →  𝐵  ∈  V ) | 
						
							| 4 | 3 | a1i | ⊢ ( 𝐴  ∈  𝑉  →  ( 𝐵  ∈  ∩  { 𝑥  ∈  Tarski  ∣  𝐴  ∈  𝑥 }  →  𝐵  ∈  V ) ) | 
						
							| 5 |  | tskmid | ⊢ ( 𝐴  ∈  𝑉  →  𝐴  ∈  ( tarskiMap ‘ 𝐴 ) ) | 
						
							| 6 |  | tskmcl | ⊢ ( tarskiMap ‘ 𝐴 )  ∈  Tarski | 
						
							| 7 |  | eleq2 | ⊢ ( 𝑥  =  ( tarskiMap ‘ 𝐴 )  →  ( 𝐴  ∈  𝑥  ↔  𝐴  ∈  ( tarskiMap ‘ 𝐴 ) ) ) | 
						
							| 8 |  | eleq2 | ⊢ ( 𝑥  =  ( tarskiMap ‘ 𝐴 )  →  ( 𝐵  ∈  𝑥  ↔  𝐵  ∈  ( tarskiMap ‘ 𝐴 ) ) ) | 
						
							| 9 | 7 8 | imbi12d | ⊢ ( 𝑥  =  ( tarskiMap ‘ 𝐴 )  →  ( ( 𝐴  ∈  𝑥  →  𝐵  ∈  𝑥 )  ↔  ( 𝐴  ∈  ( tarskiMap ‘ 𝐴 )  →  𝐵  ∈  ( tarskiMap ‘ 𝐴 ) ) ) ) | 
						
							| 10 | 9 | rspcv | ⊢ ( ( tarskiMap ‘ 𝐴 )  ∈  Tarski  →  ( ∀ 𝑥  ∈  Tarski ( 𝐴  ∈  𝑥  →  𝐵  ∈  𝑥 )  →  ( 𝐴  ∈  ( tarskiMap ‘ 𝐴 )  →  𝐵  ∈  ( tarskiMap ‘ 𝐴 ) ) ) ) | 
						
							| 11 | 6 10 | ax-mp | ⊢ ( ∀ 𝑥  ∈  Tarski ( 𝐴  ∈  𝑥  →  𝐵  ∈  𝑥 )  →  ( 𝐴  ∈  ( tarskiMap ‘ 𝐴 )  →  𝐵  ∈  ( tarskiMap ‘ 𝐴 ) ) ) | 
						
							| 12 | 5 11 | syl5com | ⊢ ( 𝐴  ∈  𝑉  →  ( ∀ 𝑥  ∈  Tarski ( 𝐴  ∈  𝑥  →  𝐵  ∈  𝑥 )  →  𝐵  ∈  ( tarskiMap ‘ 𝐴 ) ) ) | 
						
							| 13 |  | elex | ⊢ ( 𝐵  ∈  ( tarskiMap ‘ 𝐴 )  →  𝐵  ∈  V ) | 
						
							| 14 | 12 13 | syl6 | ⊢ ( 𝐴  ∈  𝑉  →  ( ∀ 𝑥  ∈  Tarski ( 𝐴  ∈  𝑥  →  𝐵  ∈  𝑥 )  →  𝐵  ∈  V ) ) | 
						
							| 15 |  | elintrabg | ⊢ ( 𝐵  ∈  V  →  ( 𝐵  ∈  ∩  { 𝑥  ∈  Tarski  ∣  𝐴  ∈  𝑥 }  ↔  ∀ 𝑥  ∈  Tarski ( 𝐴  ∈  𝑥  →  𝐵  ∈  𝑥 ) ) ) | 
						
							| 16 | 15 | a1i | ⊢ ( 𝐴  ∈  𝑉  →  ( 𝐵  ∈  V  →  ( 𝐵  ∈  ∩  { 𝑥  ∈  Tarski  ∣  𝐴  ∈  𝑥 }  ↔  ∀ 𝑥  ∈  Tarski ( 𝐴  ∈  𝑥  →  𝐵  ∈  𝑥 ) ) ) ) | 
						
							| 17 | 4 14 16 | pm5.21ndd | ⊢ ( 𝐴  ∈  𝑉  →  ( 𝐵  ∈  ∩  { 𝑥  ∈  Tarski  ∣  𝐴  ∈  𝑥 }  ↔  ∀ 𝑥  ∈  Tarski ( 𝐴  ∈  𝑥  →  𝐵  ∈  𝑥 ) ) ) | 
						
							| 18 | 2 17 | bitrd | ⊢ ( 𝐴  ∈  𝑉  →  ( 𝐵  ∈  ( tarskiMap ‘ 𝐴 )  ↔  ∀ 𝑥  ∈  Tarski ( 𝐴  ∈  𝑥  →  𝐵  ∈  𝑥 ) ) ) |