| Step | Hyp | Ref | Expression | 
						
							| 1 |  | df-ust | ⊢ UnifOn  =  ( 𝑥  ∈  V  ↦  { 𝑢  ∣  ( 𝑢  ⊆  𝒫  ( 𝑥  ×  𝑥 )  ∧  ( 𝑥  ×  𝑥 )  ∈  𝑢  ∧  ∀ 𝑣  ∈  𝑢 ( ∀ 𝑤  ∈  𝒫  ( 𝑥  ×  𝑥 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 )  ∧  ∀ 𝑤  ∈  𝑢 ( 𝑣  ∩  𝑤 )  ∈  𝑢  ∧  ( (  I   ↾  𝑥 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 ) ) ) } ) | 
						
							| 2 |  | id | ⊢ ( 𝑥  =  𝑋  →  𝑥  =  𝑋 ) | 
						
							| 3 | 2 | sqxpeqd | ⊢ ( 𝑥  =  𝑋  →  ( 𝑥  ×  𝑥 )  =  ( 𝑋  ×  𝑋 ) ) | 
						
							| 4 | 3 | pweqd | ⊢ ( 𝑥  =  𝑋  →  𝒫  ( 𝑥  ×  𝑥 )  =  𝒫  ( 𝑋  ×  𝑋 ) ) | 
						
							| 5 | 4 | sseq2d | ⊢ ( 𝑥  =  𝑋  →  ( 𝑢  ⊆  𝒫  ( 𝑥  ×  𝑥 )  ↔  𝑢  ⊆  𝒫  ( 𝑋  ×  𝑋 ) ) ) | 
						
							| 6 | 3 | eleq1d | ⊢ ( 𝑥  =  𝑋  →  ( ( 𝑥  ×  𝑥 )  ∈  𝑢  ↔  ( 𝑋  ×  𝑋 )  ∈  𝑢 ) ) | 
						
							| 7 | 4 | raleqdv | ⊢ ( 𝑥  =  𝑋  →  ( ∀ 𝑤  ∈  𝒫  ( 𝑥  ×  𝑥 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 )  ↔  ∀ 𝑤  ∈  𝒫  ( 𝑋  ×  𝑋 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 ) ) ) | 
						
							| 8 |  | reseq2 | ⊢ ( 𝑥  =  𝑋  →  (  I   ↾  𝑥 )  =  (  I   ↾  𝑋 ) ) | 
						
							| 9 | 8 | sseq1d | ⊢ ( 𝑥  =  𝑋  →  ( (  I   ↾  𝑥 )  ⊆  𝑣  ↔  (  I   ↾  𝑋 )  ⊆  𝑣 ) ) | 
						
							| 10 | 9 | 3anbi1d | ⊢ ( 𝑥  =  𝑋  →  ( ( (  I   ↾  𝑥 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 )  ↔  ( (  I   ↾  𝑋 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 ) ) ) | 
						
							| 11 | 7 10 | 3anbi13d | ⊢ ( 𝑥  =  𝑋  →  ( ( ∀ 𝑤  ∈  𝒫  ( 𝑥  ×  𝑥 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 )  ∧  ∀ 𝑤  ∈  𝑢 ( 𝑣  ∩  𝑤 )  ∈  𝑢  ∧  ( (  I   ↾  𝑥 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 ) )  ↔  ( ∀ 𝑤  ∈  𝒫  ( 𝑋  ×  𝑋 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 )  ∧  ∀ 𝑤  ∈  𝑢 ( 𝑣  ∩  𝑤 )  ∈  𝑢  ∧  ( (  I   ↾  𝑋 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 ) ) ) ) | 
						
							| 12 | 11 | ralbidv | ⊢ ( 𝑥  =  𝑋  →  ( ∀ 𝑣  ∈  𝑢 ( ∀ 𝑤  ∈  𝒫  ( 𝑥  ×  𝑥 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 )  ∧  ∀ 𝑤  ∈  𝑢 ( 𝑣  ∩  𝑤 )  ∈  𝑢  ∧  ( (  I   ↾  𝑥 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 ) )  ↔  ∀ 𝑣  ∈  𝑢 ( ∀ 𝑤  ∈  𝒫  ( 𝑋  ×  𝑋 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 )  ∧  ∀ 𝑤  ∈  𝑢 ( 𝑣  ∩  𝑤 )  ∈  𝑢  ∧  ( (  I   ↾  𝑋 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 ) ) ) ) | 
						
							| 13 | 5 6 12 | 3anbi123d | ⊢ ( 𝑥  =  𝑋  →  ( ( 𝑢  ⊆  𝒫  ( 𝑥  ×  𝑥 )  ∧  ( 𝑥  ×  𝑥 )  ∈  𝑢  ∧  ∀ 𝑣  ∈  𝑢 ( ∀ 𝑤  ∈  𝒫  ( 𝑥  ×  𝑥 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 )  ∧  ∀ 𝑤  ∈  𝑢 ( 𝑣  ∩  𝑤 )  ∈  𝑢  ∧  ( (  I   ↾  𝑥 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 ) ) )  ↔  ( 𝑢  ⊆  𝒫  ( 𝑋  ×  𝑋 )  ∧  ( 𝑋  ×  𝑋 )  ∈  𝑢  ∧  ∀ 𝑣  ∈  𝑢 ( ∀ 𝑤  ∈  𝒫  ( 𝑋  ×  𝑋 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 )  ∧  ∀ 𝑤  ∈  𝑢 ( 𝑣  ∩  𝑤 )  ∈  𝑢  ∧  ( (  I   ↾  𝑋 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 ) ) ) ) ) | 
						
							| 14 | 13 | abbidv | ⊢ ( 𝑥  =  𝑋  →  { 𝑢  ∣  ( 𝑢  ⊆  𝒫  ( 𝑥  ×  𝑥 )  ∧  ( 𝑥  ×  𝑥 )  ∈  𝑢  ∧  ∀ 𝑣  ∈  𝑢 ( ∀ 𝑤  ∈  𝒫  ( 𝑥  ×  𝑥 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 )  ∧  ∀ 𝑤  ∈  𝑢 ( 𝑣  ∩  𝑤 )  ∈  𝑢  ∧  ( (  I   ↾  𝑥 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 ) ) ) }  =  { 𝑢  ∣  ( 𝑢  ⊆  𝒫  ( 𝑋  ×  𝑋 )  ∧  ( 𝑋  ×  𝑋 )  ∈  𝑢  ∧  ∀ 𝑣  ∈  𝑢 ( ∀ 𝑤  ∈  𝒫  ( 𝑋  ×  𝑋 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 )  ∧  ∀ 𝑤  ∈  𝑢 ( 𝑣  ∩  𝑤 )  ∈  𝑢  ∧  ( (  I   ↾  𝑋 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 ) ) ) } ) | 
						
							| 15 |  | elex | ⊢ ( 𝑋  ∈  𝑉  →  𝑋  ∈  V ) | 
						
							| 16 |  | simp1 | ⊢ ( ( 𝑢  ⊆  𝒫  ( 𝑋  ×  𝑋 )  ∧  ( 𝑋  ×  𝑋 )  ∈  𝑢  ∧  ∀ 𝑣  ∈  𝑢 ( ∀ 𝑤  ∈  𝒫  ( 𝑋  ×  𝑋 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 )  ∧  ∀ 𝑤  ∈  𝑢 ( 𝑣  ∩  𝑤 )  ∈  𝑢  ∧  ( (  I   ↾  𝑋 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 ) ) )  →  𝑢  ⊆  𝒫  ( 𝑋  ×  𝑋 ) ) | 
						
							| 17 | 16 | ss2abi | ⊢ { 𝑢  ∣  ( 𝑢  ⊆  𝒫  ( 𝑋  ×  𝑋 )  ∧  ( 𝑋  ×  𝑋 )  ∈  𝑢  ∧  ∀ 𝑣  ∈  𝑢 ( ∀ 𝑤  ∈  𝒫  ( 𝑋  ×  𝑋 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 )  ∧  ∀ 𝑤  ∈  𝑢 ( 𝑣  ∩  𝑤 )  ∈  𝑢  ∧  ( (  I   ↾  𝑋 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 ) ) ) }  ⊆  { 𝑢  ∣  𝑢  ⊆  𝒫  ( 𝑋  ×  𝑋 ) } | 
						
							| 18 |  | df-pw | ⊢ 𝒫  𝒫  ( 𝑋  ×  𝑋 )  =  { 𝑢  ∣  𝑢  ⊆  𝒫  ( 𝑋  ×  𝑋 ) } | 
						
							| 19 | 17 18 | sseqtrri | ⊢ { 𝑢  ∣  ( 𝑢  ⊆  𝒫  ( 𝑋  ×  𝑋 )  ∧  ( 𝑋  ×  𝑋 )  ∈  𝑢  ∧  ∀ 𝑣  ∈  𝑢 ( ∀ 𝑤  ∈  𝒫  ( 𝑋  ×  𝑋 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 )  ∧  ∀ 𝑤  ∈  𝑢 ( 𝑣  ∩  𝑤 )  ∈  𝑢  ∧  ( (  I   ↾  𝑋 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 ) ) ) }  ⊆  𝒫  𝒫  ( 𝑋  ×  𝑋 ) | 
						
							| 20 |  | sqxpexg | ⊢ ( 𝑋  ∈  𝑉  →  ( 𝑋  ×  𝑋 )  ∈  V ) | 
						
							| 21 |  | pwexg | ⊢ ( ( 𝑋  ×  𝑋 )  ∈  V  →  𝒫  ( 𝑋  ×  𝑋 )  ∈  V ) | 
						
							| 22 |  | pwexg | ⊢ ( 𝒫  ( 𝑋  ×  𝑋 )  ∈  V  →  𝒫  𝒫  ( 𝑋  ×  𝑋 )  ∈  V ) | 
						
							| 23 | 20 21 22 | 3syl | ⊢ ( 𝑋  ∈  𝑉  →  𝒫  𝒫  ( 𝑋  ×  𝑋 )  ∈  V ) | 
						
							| 24 |  | ssexg | ⊢ ( ( { 𝑢  ∣  ( 𝑢  ⊆  𝒫  ( 𝑋  ×  𝑋 )  ∧  ( 𝑋  ×  𝑋 )  ∈  𝑢  ∧  ∀ 𝑣  ∈  𝑢 ( ∀ 𝑤  ∈  𝒫  ( 𝑋  ×  𝑋 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 )  ∧  ∀ 𝑤  ∈  𝑢 ( 𝑣  ∩  𝑤 )  ∈  𝑢  ∧  ( (  I   ↾  𝑋 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 ) ) ) }  ⊆  𝒫  𝒫  ( 𝑋  ×  𝑋 )  ∧  𝒫  𝒫  ( 𝑋  ×  𝑋 )  ∈  V )  →  { 𝑢  ∣  ( 𝑢  ⊆  𝒫  ( 𝑋  ×  𝑋 )  ∧  ( 𝑋  ×  𝑋 )  ∈  𝑢  ∧  ∀ 𝑣  ∈  𝑢 ( ∀ 𝑤  ∈  𝒫  ( 𝑋  ×  𝑋 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 )  ∧  ∀ 𝑤  ∈  𝑢 ( 𝑣  ∩  𝑤 )  ∈  𝑢  ∧  ( (  I   ↾  𝑋 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 ) ) ) }  ∈  V ) | 
						
							| 25 | 19 23 24 | sylancr | ⊢ ( 𝑋  ∈  𝑉  →  { 𝑢  ∣  ( 𝑢  ⊆  𝒫  ( 𝑋  ×  𝑋 )  ∧  ( 𝑋  ×  𝑋 )  ∈  𝑢  ∧  ∀ 𝑣  ∈  𝑢 ( ∀ 𝑤  ∈  𝒫  ( 𝑋  ×  𝑋 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 )  ∧  ∀ 𝑤  ∈  𝑢 ( 𝑣  ∩  𝑤 )  ∈  𝑢  ∧  ( (  I   ↾  𝑋 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 ) ) ) }  ∈  V ) | 
						
							| 26 | 1 14 15 25 | fvmptd3 | ⊢ ( 𝑋  ∈  𝑉  →  ( UnifOn ‘ 𝑋 )  =  { 𝑢  ∣  ( 𝑢  ⊆  𝒫  ( 𝑋  ×  𝑋 )  ∧  ( 𝑋  ×  𝑋 )  ∈  𝑢  ∧  ∀ 𝑣  ∈  𝑢 ( ∀ 𝑤  ∈  𝒫  ( 𝑋  ×  𝑋 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑢 )  ∧  ∀ 𝑤  ∈  𝑢 ( 𝑣  ∩  𝑤 )  ∈  𝑢  ∧  ( (  I   ↾  𝑋 )  ⊆  𝑣  ∧  ◡ 𝑣  ∈  𝑢  ∧  ∃ 𝑤  ∈  𝑢 ( 𝑤  ∘  𝑤 )  ⊆  𝑣 ) ) ) } ) |