| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ntrcls.o | ⊢ 𝑂  =  ( 𝑖  ∈  V  ↦  ( 𝑘  ∈  ( 𝒫  𝑖  ↑m  𝒫  𝑖 )  ↦  ( 𝑗  ∈  𝒫  𝑖  ↦  ( 𝑖  ∖  ( 𝑘 ‘ ( 𝑖  ∖  𝑗 ) ) ) ) ) ) | 
						
							| 2 |  | ntrcls.d | ⊢ 𝐷  =  ( 𝑂 ‘ 𝐵 ) | 
						
							| 3 |  | ntrcls.r | ⊢ ( 𝜑  →  𝐼 𝐷 𝐾 ) | 
						
							| 4 |  | ntrclsfv.s | ⊢ ( 𝜑  →  𝑆  ∈  𝒫  𝐵 ) | 
						
							| 5 |  | ntrclsfv.t | ⊢ ( 𝜑  →  𝑇  ∈  𝒫  𝐵 ) | 
						
							| 6 | 1 2 3 4 | ntrclsfv | ⊢ ( 𝜑  →  ( 𝐼 ‘ 𝑆 )  =  ( 𝐵  ∖  ( 𝐾 ‘ ( 𝐵  ∖  𝑆 ) ) ) ) | 
						
							| 7 | 1 2 3 5 | ntrclsfv | ⊢ ( 𝜑  →  ( 𝐼 ‘ 𝑇 )  =  ( 𝐵  ∖  ( 𝐾 ‘ ( 𝐵  ∖  𝑇 ) ) ) ) | 
						
							| 8 | 6 7 | sseq12d | ⊢ ( 𝜑  →  ( ( 𝐼 ‘ 𝑆 )  ⊆  ( 𝐼 ‘ 𝑇 )  ↔  ( 𝐵  ∖  ( 𝐾 ‘ ( 𝐵  ∖  𝑆 ) ) )  ⊆  ( 𝐵  ∖  ( 𝐾 ‘ ( 𝐵  ∖  𝑇 ) ) ) ) ) | 
						
							| 9 | 1 2 3 | ntrclskex | ⊢ ( 𝜑  →  𝐾  ∈  ( 𝒫  𝐵  ↑m  𝒫  𝐵 ) ) | 
						
							| 10 | 9 | ancli | ⊢ ( 𝜑  →  ( 𝜑  ∧  𝐾  ∈  ( 𝒫  𝐵  ↑m  𝒫  𝐵 ) ) ) | 
						
							| 11 |  | elmapi | ⊢ ( 𝐾  ∈  ( 𝒫  𝐵  ↑m  𝒫  𝐵 )  →  𝐾 : 𝒫  𝐵 ⟶ 𝒫  𝐵 ) | 
						
							| 12 | 11 | adantl | ⊢ ( ( 𝜑  ∧  𝐾  ∈  ( 𝒫  𝐵  ↑m  𝒫  𝐵 ) )  →  𝐾 : 𝒫  𝐵 ⟶ 𝒫  𝐵 ) | 
						
							| 13 | 2 3 | ntrclsrcomplex | ⊢ ( 𝜑  →  ( 𝐵  ∖  𝑇 )  ∈  𝒫  𝐵 ) | 
						
							| 14 | 13 | adantr | ⊢ ( ( 𝜑  ∧  𝐾  ∈  ( 𝒫  𝐵  ↑m  𝒫  𝐵 ) )  →  ( 𝐵  ∖  𝑇 )  ∈  𝒫  𝐵 ) | 
						
							| 15 | 12 14 | ffvelcdmd | ⊢ ( ( 𝜑  ∧  𝐾  ∈  ( 𝒫  𝐵  ↑m  𝒫  𝐵 ) )  →  ( 𝐾 ‘ ( 𝐵  ∖  𝑇 ) )  ∈  𝒫  𝐵 ) | 
						
							| 16 | 15 | elpwid | ⊢ ( ( 𝜑  ∧  𝐾  ∈  ( 𝒫  𝐵  ↑m  𝒫  𝐵 ) )  →  ( 𝐾 ‘ ( 𝐵  ∖  𝑇 ) )  ⊆  𝐵 ) | 
						
							| 17 | 2 3 | ntrclsrcomplex | ⊢ ( 𝜑  →  ( 𝐵  ∖  𝑆 )  ∈  𝒫  𝐵 ) | 
						
							| 18 | 17 | adantr | ⊢ ( ( 𝜑  ∧  𝐾  ∈  ( 𝒫  𝐵  ↑m  𝒫  𝐵 ) )  →  ( 𝐵  ∖  𝑆 )  ∈  𝒫  𝐵 ) | 
						
							| 19 | 12 18 | ffvelcdmd | ⊢ ( ( 𝜑  ∧  𝐾  ∈  ( 𝒫  𝐵  ↑m  𝒫  𝐵 ) )  →  ( 𝐾 ‘ ( 𝐵  ∖  𝑆 ) )  ∈  𝒫  𝐵 ) | 
						
							| 20 | 19 | elpwid | ⊢ ( ( 𝜑  ∧  𝐾  ∈  ( 𝒫  𝐵  ↑m  𝒫  𝐵 ) )  →  ( 𝐾 ‘ ( 𝐵  ∖  𝑆 ) )  ⊆  𝐵 ) | 
						
							| 21 | 16 20 | jca | ⊢ ( ( 𝜑  ∧  𝐾  ∈  ( 𝒫  𝐵  ↑m  𝒫  𝐵 ) )  →  ( ( 𝐾 ‘ ( 𝐵  ∖  𝑇 ) )  ⊆  𝐵  ∧  ( 𝐾 ‘ ( 𝐵  ∖  𝑆 ) )  ⊆  𝐵 ) ) | 
						
							| 22 |  | sscon34b | ⊢ ( ( ( 𝐾 ‘ ( 𝐵  ∖  𝑇 ) )  ⊆  𝐵  ∧  ( 𝐾 ‘ ( 𝐵  ∖  𝑆 ) )  ⊆  𝐵 )  →  ( ( 𝐾 ‘ ( 𝐵  ∖  𝑇 ) )  ⊆  ( 𝐾 ‘ ( 𝐵  ∖  𝑆 ) )  ↔  ( 𝐵  ∖  ( 𝐾 ‘ ( 𝐵  ∖  𝑆 ) ) )  ⊆  ( 𝐵  ∖  ( 𝐾 ‘ ( 𝐵  ∖  𝑇 ) ) ) ) ) | 
						
							| 23 | 10 21 22 | 3syl | ⊢ ( 𝜑  →  ( ( 𝐾 ‘ ( 𝐵  ∖  𝑇 ) )  ⊆  ( 𝐾 ‘ ( 𝐵  ∖  𝑆 ) )  ↔  ( 𝐵  ∖  ( 𝐾 ‘ ( 𝐵  ∖  𝑆 ) ) )  ⊆  ( 𝐵  ∖  ( 𝐾 ‘ ( 𝐵  ∖  𝑇 ) ) ) ) ) | 
						
							| 24 | 8 23 | bitr4d | ⊢ ( 𝜑  →  ( ( 𝐼 ‘ 𝑆 )  ⊆  ( 𝐼 ‘ 𝑇 )  ↔  ( 𝐾 ‘ ( 𝐵  ∖  𝑇 ) )  ⊆  ( 𝐾 ‘ ( 𝐵  ∖  𝑆 ) ) ) ) |