| Step | Hyp | Ref | Expression | 
						
							| 1 |  | simp1 | ⊢ ( ( 𝑈  ∈  ( UnifOn ‘ 𝑋 )  ∧  𝑉  ∈  𝑈  ∧  𝑊  ⊆  ( 𝑋  ×  𝑋 ) )  →  𝑈  ∈  ( UnifOn ‘ 𝑋 ) ) | 
						
							| 2 | 1 | elfvexd | ⊢ ( ( 𝑈  ∈  ( UnifOn ‘ 𝑋 )  ∧  𝑉  ∈  𝑈  ∧  𝑊  ⊆  ( 𝑋  ×  𝑋 ) )  →  𝑋  ∈  V ) | 
						
							| 3 |  | isust | ⊢ ( 𝑋  ∈  V  →  ( 𝑈  ∈  ( UnifOn ‘ 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 ) ) ) ) ) | 
						
							| 4 | 2 3 | syl | ⊢ ( ( 𝑈  ∈  ( UnifOn ‘ 𝑋 )  ∧  𝑉  ∈  𝑈  ∧  𝑊  ⊆  ( 𝑋  ×  𝑋 ) )  →  ( 𝑈  ∈  ( UnifOn ‘ 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 ) ) ) ) ) | 
						
							| 5 | 1 4 | mpbid | ⊢ ( ( 𝑈  ∈  ( UnifOn ‘ 𝑋 )  ∧  𝑉  ∈  𝑈  ∧  𝑊  ⊆  ( 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 ) ) ) ) | 
						
							| 6 | 5 | simp3d | ⊢ ( ( 𝑈  ∈  ( UnifOn ‘ 𝑋 )  ∧  𝑉  ∈  𝑈  ∧  𝑊  ⊆  ( 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 ) ) ) | 
						
							| 7 |  | simp1 | ⊢ ( ( ∀ 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 ) ) | 
						
							| 8 | 7 | ralimi | ⊢ ( ∀ 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 ) ) | 
						
							| 9 | 6 8 | syl | ⊢ ( ( 𝑈  ∈  ( UnifOn ‘ 𝑋 )  ∧  𝑉  ∈  𝑈  ∧  𝑊  ⊆  ( 𝑋  ×  𝑋 ) )  →  ∀ 𝑣  ∈  𝑈 ∀ 𝑤  ∈  𝒫  ( 𝑋  ×  𝑋 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑈 ) ) | 
						
							| 10 |  | simp2 | ⊢ ( ( 𝑈  ∈  ( UnifOn ‘ 𝑋 )  ∧  𝑉  ∈  𝑈  ∧  𝑊  ⊆  ( 𝑋  ×  𝑋 ) )  →  𝑉  ∈  𝑈 ) | 
						
							| 11 | 2 2 | xpexd | ⊢ ( ( 𝑈  ∈  ( UnifOn ‘ 𝑋 )  ∧  𝑉  ∈  𝑈  ∧  𝑊  ⊆  ( 𝑋  ×  𝑋 ) )  →  ( 𝑋  ×  𝑋 )  ∈  V ) | 
						
							| 12 |  | simp3 | ⊢ ( ( 𝑈  ∈  ( UnifOn ‘ 𝑋 )  ∧  𝑉  ∈  𝑈  ∧  𝑊  ⊆  ( 𝑋  ×  𝑋 ) )  →  𝑊  ⊆  ( 𝑋  ×  𝑋 ) ) | 
						
							| 13 | 11 12 | sselpwd | ⊢ ( ( 𝑈  ∈  ( UnifOn ‘ 𝑋 )  ∧  𝑉  ∈  𝑈  ∧  𝑊  ⊆  ( 𝑋  ×  𝑋 ) )  →  𝑊  ∈  𝒫  ( 𝑋  ×  𝑋 ) ) | 
						
							| 14 |  | sseq1 | ⊢ ( 𝑣  =  𝑉  →  ( 𝑣  ⊆  𝑤  ↔  𝑉  ⊆  𝑤 ) ) | 
						
							| 15 | 14 | imbi1d | ⊢ ( 𝑣  =  𝑉  →  ( ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑈 )  ↔  ( 𝑉  ⊆  𝑤  →  𝑤  ∈  𝑈 ) ) ) | 
						
							| 16 |  | sseq2 | ⊢ ( 𝑤  =  𝑊  →  ( 𝑉  ⊆  𝑤  ↔  𝑉  ⊆  𝑊 ) ) | 
						
							| 17 |  | eleq1 | ⊢ ( 𝑤  =  𝑊  →  ( 𝑤  ∈  𝑈  ↔  𝑊  ∈  𝑈 ) ) | 
						
							| 18 | 16 17 | imbi12d | ⊢ ( 𝑤  =  𝑊  →  ( ( 𝑉  ⊆  𝑤  →  𝑤  ∈  𝑈 )  ↔  ( 𝑉  ⊆  𝑊  →  𝑊  ∈  𝑈 ) ) ) | 
						
							| 19 | 15 18 | rspc2v | ⊢ ( ( 𝑉  ∈  𝑈  ∧  𝑊  ∈  𝒫  ( 𝑋  ×  𝑋 ) )  →  ( ∀ 𝑣  ∈  𝑈 ∀ 𝑤  ∈  𝒫  ( 𝑋  ×  𝑋 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑈 )  →  ( 𝑉  ⊆  𝑊  →  𝑊  ∈  𝑈 ) ) ) | 
						
							| 20 | 10 13 19 | syl2anc | ⊢ ( ( 𝑈  ∈  ( UnifOn ‘ 𝑋 )  ∧  𝑉  ∈  𝑈  ∧  𝑊  ⊆  ( 𝑋  ×  𝑋 ) )  →  ( ∀ 𝑣  ∈  𝑈 ∀ 𝑤  ∈  𝒫  ( 𝑋  ×  𝑋 ) ( 𝑣  ⊆  𝑤  →  𝑤  ∈  𝑈 )  →  ( 𝑉  ⊆  𝑊  →  𝑊  ∈  𝑈 ) ) ) | 
						
							| 21 | 9 20 | mpd | ⊢ ( ( 𝑈  ∈  ( UnifOn ‘ 𝑋 )  ∧  𝑉  ∈  𝑈  ∧  𝑊  ⊆  ( 𝑋  ×  𝑋 ) )  →  ( 𝑉  ⊆  𝑊  →  𝑊  ∈  𝑈 ) ) |