| Step | Hyp | Ref | Expression | 
						
							| 1 |  | elfvex | ⊢ ( 𝐶  ∈  ( Moore ‘ 𝑋 )  →  𝑋  ∈  V ) | 
						
							| 2 |  | elex | ⊢ ( 𝑋  ∈  𝐶  →  𝑋  ∈  V ) | 
						
							| 3 | 2 | 3ad2ant2 | ⊢ ( ( 𝐶  ⊆  𝒫  𝑋  ∧  𝑋  ∈  𝐶  ∧  ∀ 𝑠  ∈  𝒫  𝐶 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝐶 ) )  →  𝑋  ∈  V ) | 
						
							| 4 |  | pweq | ⊢ ( 𝑥  =  𝑋  →  𝒫  𝑥  =  𝒫  𝑋 ) | 
						
							| 5 | 4 | pweqd | ⊢ ( 𝑥  =  𝑋  →  𝒫  𝒫  𝑥  =  𝒫  𝒫  𝑋 ) | 
						
							| 6 |  | eleq1 | ⊢ ( 𝑥  =  𝑋  →  ( 𝑥  ∈  𝑐  ↔  𝑋  ∈  𝑐 ) ) | 
						
							| 7 | 6 | anbi1d | ⊢ ( 𝑥  =  𝑋  →  ( ( 𝑥  ∈  𝑐  ∧  ∀ 𝑠  ∈  𝒫  𝑐 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝑐 ) )  ↔  ( 𝑋  ∈  𝑐  ∧  ∀ 𝑠  ∈  𝒫  𝑐 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝑐 ) ) ) ) | 
						
							| 8 | 5 7 | rabeqbidv | ⊢ ( 𝑥  =  𝑋  →  { 𝑐  ∈  𝒫  𝒫  𝑥  ∣  ( 𝑥  ∈  𝑐  ∧  ∀ 𝑠  ∈  𝒫  𝑐 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝑐 ) ) }  =  { 𝑐  ∈  𝒫  𝒫  𝑋  ∣  ( 𝑋  ∈  𝑐  ∧  ∀ 𝑠  ∈  𝒫  𝑐 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝑐 ) ) } ) | 
						
							| 9 |  | df-mre | ⊢ Moore  =  ( 𝑥  ∈  V  ↦  { 𝑐  ∈  𝒫  𝒫  𝑥  ∣  ( 𝑥  ∈  𝑐  ∧  ∀ 𝑠  ∈  𝒫  𝑐 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝑐 ) ) } ) | 
						
							| 10 |  | vpwex | ⊢ 𝒫  𝑥  ∈  V | 
						
							| 11 | 10 | pwex | ⊢ 𝒫  𝒫  𝑥  ∈  V | 
						
							| 12 | 11 | rabex | ⊢ { 𝑐  ∈  𝒫  𝒫  𝑥  ∣  ( 𝑥  ∈  𝑐  ∧  ∀ 𝑠  ∈  𝒫  𝑐 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝑐 ) ) }  ∈  V | 
						
							| 13 | 8 9 12 | fvmpt3i | ⊢ ( 𝑋  ∈  V  →  ( Moore ‘ 𝑋 )  =  { 𝑐  ∈  𝒫  𝒫  𝑋  ∣  ( 𝑋  ∈  𝑐  ∧  ∀ 𝑠  ∈  𝒫  𝑐 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝑐 ) ) } ) | 
						
							| 14 | 13 | eleq2d | ⊢ ( 𝑋  ∈  V  →  ( 𝐶  ∈  ( Moore ‘ 𝑋 )  ↔  𝐶  ∈  { 𝑐  ∈  𝒫  𝒫  𝑋  ∣  ( 𝑋  ∈  𝑐  ∧  ∀ 𝑠  ∈  𝒫  𝑐 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝑐 ) ) } ) ) | 
						
							| 15 |  | eleq2 | ⊢ ( 𝑐  =  𝐶  →  ( 𝑋  ∈  𝑐  ↔  𝑋  ∈  𝐶 ) ) | 
						
							| 16 |  | pweq | ⊢ ( 𝑐  =  𝐶  →  𝒫  𝑐  =  𝒫  𝐶 ) | 
						
							| 17 |  | eleq2 | ⊢ ( 𝑐  =  𝐶  →  ( ∩  𝑠  ∈  𝑐  ↔  ∩  𝑠  ∈  𝐶 ) ) | 
						
							| 18 | 17 | imbi2d | ⊢ ( 𝑐  =  𝐶  →  ( ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝑐 )  ↔  ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝐶 ) ) ) | 
						
							| 19 | 16 18 | raleqbidv | ⊢ ( 𝑐  =  𝐶  →  ( ∀ 𝑠  ∈  𝒫  𝑐 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝑐 )  ↔  ∀ 𝑠  ∈  𝒫  𝐶 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝐶 ) ) ) | 
						
							| 20 | 15 19 | anbi12d | ⊢ ( 𝑐  =  𝐶  →  ( ( 𝑋  ∈  𝑐  ∧  ∀ 𝑠  ∈  𝒫  𝑐 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝑐 ) )  ↔  ( 𝑋  ∈  𝐶  ∧  ∀ 𝑠  ∈  𝒫  𝐶 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝐶 ) ) ) ) | 
						
							| 21 | 20 | elrab | ⊢ ( 𝐶  ∈  { 𝑐  ∈  𝒫  𝒫  𝑋  ∣  ( 𝑋  ∈  𝑐  ∧  ∀ 𝑠  ∈  𝒫  𝑐 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝑐 ) ) }  ↔  ( 𝐶  ∈  𝒫  𝒫  𝑋  ∧  ( 𝑋  ∈  𝐶  ∧  ∀ 𝑠  ∈  𝒫  𝐶 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝐶 ) ) ) ) | 
						
							| 22 | 21 | a1i | ⊢ ( 𝑋  ∈  V  →  ( 𝐶  ∈  { 𝑐  ∈  𝒫  𝒫  𝑋  ∣  ( 𝑋  ∈  𝑐  ∧  ∀ 𝑠  ∈  𝒫  𝑐 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝑐 ) ) }  ↔  ( 𝐶  ∈  𝒫  𝒫  𝑋  ∧  ( 𝑋  ∈  𝐶  ∧  ∀ 𝑠  ∈  𝒫  𝐶 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝐶 ) ) ) ) ) | 
						
							| 23 |  | pwexg | ⊢ ( 𝑋  ∈  V  →  𝒫  𝑋  ∈  V ) | 
						
							| 24 |  | elpw2g | ⊢ ( 𝒫  𝑋  ∈  V  →  ( 𝐶  ∈  𝒫  𝒫  𝑋  ↔  𝐶  ⊆  𝒫  𝑋 ) ) | 
						
							| 25 | 23 24 | syl | ⊢ ( 𝑋  ∈  V  →  ( 𝐶  ∈  𝒫  𝒫  𝑋  ↔  𝐶  ⊆  𝒫  𝑋 ) ) | 
						
							| 26 | 25 | anbi1d | ⊢ ( 𝑋  ∈  V  →  ( ( 𝐶  ∈  𝒫  𝒫  𝑋  ∧  ( 𝑋  ∈  𝐶  ∧  ∀ 𝑠  ∈  𝒫  𝐶 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝐶 ) ) )  ↔  ( 𝐶  ⊆  𝒫  𝑋  ∧  ( 𝑋  ∈  𝐶  ∧  ∀ 𝑠  ∈  𝒫  𝐶 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝐶 ) ) ) ) ) | 
						
							| 27 |  | 3anass | ⊢ ( ( 𝐶  ⊆  𝒫  𝑋  ∧  𝑋  ∈  𝐶  ∧  ∀ 𝑠  ∈  𝒫  𝐶 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝐶 ) )  ↔  ( 𝐶  ⊆  𝒫  𝑋  ∧  ( 𝑋  ∈  𝐶  ∧  ∀ 𝑠  ∈  𝒫  𝐶 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝐶 ) ) ) ) | 
						
							| 28 | 26 27 | bitr4di | ⊢ ( 𝑋  ∈  V  →  ( ( 𝐶  ∈  𝒫  𝒫  𝑋  ∧  ( 𝑋  ∈  𝐶  ∧  ∀ 𝑠  ∈  𝒫  𝐶 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝐶 ) ) )  ↔  ( 𝐶  ⊆  𝒫  𝑋  ∧  𝑋  ∈  𝐶  ∧  ∀ 𝑠  ∈  𝒫  𝐶 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝐶 ) ) ) ) | 
						
							| 29 | 14 22 28 | 3bitrd | ⊢ ( 𝑋  ∈  V  →  ( 𝐶  ∈  ( Moore ‘ 𝑋 )  ↔  ( 𝐶  ⊆  𝒫  𝑋  ∧  𝑋  ∈  𝐶  ∧  ∀ 𝑠  ∈  𝒫  𝐶 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝐶 ) ) ) ) | 
						
							| 30 | 1 3 29 | pm5.21nii | ⊢ ( 𝐶  ∈  ( Moore ‘ 𝑋 )  ↔  ( 𝐶  ⊆  𝒫  𝑋  ∧  𝑋  ∈  𝐶  ∧  ∀ 𝑠  ∈  𝒫  𝐶 ( 𝑠  ≠  ∅  →  ∩  𝑠  ∈  𝐶 ) ) ) |