| Step | Hyp | Ref | Expression | 
						
							| 1 |  | simp1 | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  𝐽  ∈  ( TopOn ‘ 𝑋 ) ) | 
						
							| 2 |  | filelss | ⊢ ( ( 𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  𝑌  ⊆  𝑋 ) | 
						
							| 3 | 2 | 3adant1 | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  𝑌  ⊆  𝑋 ) | 
						
							| 4 |  | resttopon | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝑌  ⊆  𝑋 )  →  ( 𝐽  ↾t  𝑌 )  ∈  ( TopOn ‘ 𝑌 ) ) | 
						
							| 5 | 1 3 4 | syl2anc | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  ( 𝐽  ↾t  𝑌 )  ∈  ( TopOn ‘ 𝑌 ) ) | 
						
							| 6 |  | filfbas | ⊢ ( 𝐹  ∈  ( Fil ‘ 𝑋 )  →  𝐹  ∈  ( fBas ‘ 𝑋 ) ) | 
						
							| 7 | 6 | 3ad2ant2 | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  𝐹  ∈  ( fBas ‘ 𝑋 ) ) | 
						
							| 8 |  | simp3 | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  𝑌  ∈  𝐹 ) | 
						
							| 9 |  | fbncp | ⊢ ( ( 𝐹  ∈  ( fBas ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  ¬  ( 𝑋  ∖  𝑌 )  ∈  𝐹 ) | 
						
							| 10 | 7 8 9 | syl2anc | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  ¬  ( 𝑋  ∖  𝑌 )  ∈  𝐹 ) | 
						
							| 11 |  | simp2 | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  𝐹  ∈  ( Fil ‘ 𝑋 ) ) | 
						
							| 12 |  | trfil3 | ⊢ ( ( 𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ⊆  𝑋 )  →  ( ( 𝐹  ↾t  𝑌 )  ∈  ( Fil ‘ 𝑌 )  ↔  ¬  ( 𝑋  ∖  𝑌 )  ∈  𝐹 ) ) | 
						
							| 13 | 11 3 12 | syl2anc | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  ( ( 𝐹  ↾t  𝑌 )  ∈  ( Fil ‘ 𝑌 )  ↔  ¬  ( 𝑋  ∖  𝑌 )  ∈  𝐹 ) ) | 
						
							| 14 | 10 13 | mpbird | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  ( 𝐹  ↾t  𝑌 )  ∈  ( Fil ‘ 𝑌 ) ) | 
						
							| 15 |  | fclsopn | ⊢ ( ( ( 𝐽  ↾t  𝑌 )  ∈  ( TopOn ‘ 𝑌 )  ∧  ( 𝐹  ↾t  𝑌 )  ∈  ( Fil ‘ 𝑌 ) )  →  ( 𝑥  ∈  ( ( 𝐽  ↾t  𝑌 )  fClus  ( 𝐹  ↾t  𝑌 ) )  ↔  ( 𝑥  ∈  𝑌  ∧  ∀ 𝑦  ∈  ( 𝐽  ↾t  𝑌 ) ( 𝑥  ∈  𝑦  →  ∀ 𝑧  ∈  ( 𝐹  ↾t  𝑌 ) ( 𝑦  ∩  𝑧 )  ≠  ∅ ) ) ) ) | 
						
							| 16 | 5 14 15 | syl2anc | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  ( 𝑥  ∈  ( ( 𝐽  ↾t  𝑌 )  fClus  ( 𝐹  ↾t  𝑌 ) )  ↔  ( 𝑥  ∈  𝑌  ∧  ∀ 𝑦  ∈  ( 𝐽  ↾t  𝑌 ) ( 𝑥  ∈  𝑦  →  ∀ 𝑧  ∈  ( 𝐹  ↾t  𝑌 ) ( 𝑦  ∩  𝑧 )  ≠  ∅ ) ) ) ) | 
						
							| 17 |  | in32 | ⊢ ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  =  ( ( 𝑢  ∩  𝑌 )  ∩  𝑠 ) | 
						
							| 18 |  | ineq2 | ⊢ ( 𝑠  =  𝑡  →  ( ( 𝑢  ∩  𝑌 )  ∩  𝑠 )  =  ( ( 𝑢  ∩  𝑌 )  ∩  𝑡 ) ) | 
						
							| 19 | 17 18 | eqtrid | ⊢ ( 𝑠  =  𝑡  →  ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  =  ( ( 𝑢  ∩  𝑌 )  ∩  𝑡 ) ) | 
						
							| 20 | 19 | neeq1d | ⊢ ( 𝑠  =  𝑡  →  ( ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  ≠  ∅  ↔  ( ( 𝑢  ∩  𝑌 )  ∩  𝑡 )  ≠  ∅ ) ) | 
						
							| 21 | 20 | rspccv | ⊢ ( ∀ 𝑠  ∈  𝐹 ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  ≠  ∅  →  ( 𝑡  ∈  𝐹  →  ( ( 𝑢  ∩  𝑌 )  ∩  𝑡 )  ≠  ∅ ) ) | 
						
							| 22 |  | inss1 | ⊢ ( 𝑢  ∩  𝑌 )  ⊆  𝑢 | 
						
							| 23 |  | ssrin | ⊢ ( ( 𝑢  ∩  𝑌 )  ⊆  𝑢  →  ( ( 𝑢  ∩  𝑌 )  ∩  𝑡 )  ⊆  ( 𝑢  ∩  𝑡 ) ) | 
						
							| 24 | 22 23 | ax-mp | ⊢ ( ( 𝑢  ∩  𝑌 )  ∩  𝑡 )  ⊆  ( 𝑢  ∩  𝑡 ) | 
						
							| 25 |  | ssn0 | ⊢ ( ( ( ( 𝑢  ∩  𝑌 )  ∩  𝑡 )  ⊆  ( 𝑢  ∩  𝑡 )  ∧  ( ( 𝑢  ∩  𝑌 )  ∩  𝑡 )  ≠  ∅ )  →  ( 𝑢  ∩  𝑡 )  ≠  ∅ ) | 
						
							| 26 | 24 25 | mpan | ⊢ ( ( ( 𝑢  ∩  𝑌 )  ∩  𝑡 )  ≠  ∅  →  ( 𝑢  ∩  𝑡 )  ≠  ∅ ) | 
						
							| 27 | 21 26 | syl6 | ⊢ ( ∀ 𝑠  ∈  𝐹 ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  ≠  ∅  →  ( 𝑡  ∈  𝐹  →  ( 𝑢  ∩  𝑡 )  ≠  ∅ ) ) | 
						
							| 28 | 27 | ralrimiv | ⊢ ( ∀ 𝑠  ∈  𝐹 ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  ≠  ∅  →  ∀ 𝑡  ∈  𝐹 ( 𝑢  ∩  𝑡 )  ≠  ∅ ) | 
						
							| 29 | 11 | ad3antrrr | ⊢ ( ( ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  ∧  𝑢  ∈  𝐽 )  ∧  𝑠  ∈  𝐹 )  →  𝐹  ∈  ( Fil ‘ 𝑋 ) ) | 
						
							| 30 |  | simpr | ⊢ ( ( ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  ∧  𝑢  ∈  𝐽 )  ∧  𝑠  ∈  𝐹 )  →  𝑠  ∈  𝐹 ) | 
						
							| 31 | 8 | ad3antrrr | ⊢ ( ( ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  ∧  𝑢  ∈  𝐽 )  ∧  𝑠  ∈  𝐹 )  →  𝑌  ∈  𝐹 ) | 
						
							| 32 |  | filin | ⊢ ( ( 𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑠  ∈  𝐹  ∧  𝑌  ∈  𝐹 )  →  ( 𝑠  ∩  𝑌 )  ∈  𝐹 ) | 
						
							| 33 | 29 30 31 32 | syl3anc | ⊢ ( ( ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  ∧  𝑢  ∈  𝐽 )  ∧  𝑠  ∈  𝐹 )  →  ( 𝑠  ∩  𝑌 )  ∈  𝐹 ) | 
						
							| 34 |  | ineq2 | ⊢ ( 𝑡  =  ( 𝑠  ∩  𝑌 )  →  ( 𝑢  ∩  𝑡 )  =  ( 𝑢  ∩  ( 𝑠  ∩  𝑌 ) ) ) | 
						
							| 35 |  | inass | ⊢ ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  =  ( 𝑢  ∩  ( 𝑠  ∩  𝑌 ) ) | 
						
							| 36 | 34 35 | eqtr4di | ⊢ ( 𝑡  =  ( 𝑠  ∩  𝑌 )  →  ( 𝑢  ∩  𝑡 )  =  ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 ) ) | 
						
							| 37 | 36 | neeq1d | ⊢ ( 𝑡  =  ( 𝑠  ∩  𝑌 )  →  ( ( 𝑢  ∩  𝑡 )  ≠  ∅  ↔  ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  ≠  ∅ ) ) | 
						
							| 38 | 37 | rspcv | ⊢ ( ( 𝑠  ∩  𝑌 )  ∈  𝐹  →  ( ∀ 𝑡  ∈  𝐹 ( 𝑢  ∩  𝑡 )  ≠  ∅  →  ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  ≠  ∅ ) ) | 
						
							| 39 | 33 38 | syl | ⊢ ( ( ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  ∧  𝑢  ∈  𝐽 )  ∧  𝑠  ∈  𝐹 )  →  ( ∀ 𝑡  ∈  𝐹 ( 𝑢  ∩  𝑡 )  ≠  ∅  →  ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  ≠  ∅ ) ) | 
						
							| 40 | 39 | ralrimdva | ⊢ ( ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  ∧  𝑢  ∈  𝐽 )  →  ( ∀ 𝑡  ∈  𝐹 ( 𝑢  ∩  𝑡 )  ≠  ∅  →  ∀ 𝑠  ∈  𝐹 ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  ≠  ∅ ) ) | 
						
							| 41 | 28 40 | impbid2 | ⊢ ( ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  ∧  𝑢  ∈  𝐽 )  →  ( ∀ 𝑠  ∈  𝐹 ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  ≠  ∅  ↔  ∀ 𝑡  ∈  𝐹 ( 𝑢  ∩  𝑡 )  ≠  ∅ ) ) | 
						
							| 42 | 41 | imbi2d | ⊢ ( ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  ∧  𝑢  ∈  𝐽 )  →  ( ( 𝑥  ∈  𝑢  →  ∀ 𝑠  ∈  𝐹 ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  ≠  ∅ )  ↔  ( 𝑥  ∈  𝑢  →  ∀ 𝑡  ∈  𝐹 ( 𝑢  ∩  𝑡 )  ≠  ∅ ) ) ) | 
						
							| 43 | 42 | ralbidva | ⊢ ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  →  ( ∀ 𝑢  ∈  𝐽 ( 𝑥  ∈  𝑢  →  ∀ 𝑠  ∈  𝐹 ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  ≠  ∅ )  ↔  ∀ 𝑢  ∈  𝐽 ( 𝑥  ∈  𝑢  →  ∀ 𝑡  ∈  𝐹 ( 𝑢  ∩  𝑡 )  ≠  ∅ ) ) ) | 
						
							| 44 |  | vex | ⊢ 𝑢  ∈  V | 
						
							| 45 | 44 | inex1 | ⊢ ( 𝑢  ∩  𝑌 )  ∈  V | 
						
							| 46 | 45 | a1i | ⊢ ( ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  ∧  𝑢  ∈  𝐽 )  →  ( 𝑢  ∩  𝑌 )  ∈  V ) | 
						
							| 47 |  | elrest | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  ( 𝑦  ∈  ( 𝐽  ↾t  𝑌 )  ↔  ∃ 𝑢  ∈  𝐽 𝑦  =  ( 𝑢  ∩  𝑌 ) ) ) | 
						
							| 48 | 47 | 3adant2 | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  ( 𝑦  ∈  ( 𝐽  ↾t  𝑌 )  ↔  ∃ 𝑢  ∈  𝐽 𝑦  =  ( 𝑢  ∩  𝑌 ) ) ) | 
						
							| 49 | 48 | adantr | ⊢ ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  →  ( 𝑦  ∈  ( 𝐽  ↾t  𝑌 )  ↔  ∃ 𝑢  ∈  𝐽 𝑦  =  ( 𝑢  ∩  𝑌 ) ) ) | 
						
							| 50 |  | eleq2 | ⊢ ( 𝑦  =  ( 𝑢  ∩  𝑌 )  →  ( 𝑥  ∈  𝑦  ↔  𝑥  ∈  ( 𝑢  ∩  𝑌 ) ) ) | 
						
							| 51 |  | elin | ⊢ ( 𝑥  ∈  ( 𝑢  ∩  𝑌 )  ↔  ( 𝑥  ∈  𝑢  ∧  𝑥  ∈  𝑌 ) ) | 
						
							| 52 | 51 | rbaib | ⊢ ( 𝑥  ∈  𝑌  →  ( 𝑥  ∈  ( 𝑢  ∩  𝑌 )  ↔  𝑥  ∈  𝑢 ) ) | 
						
							| 53 | 52 | adantl | ⊢ ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  →  ( 𝑥  ∈  ( 𝑢  ∩  𝑌 )  ↔  𝑥  ∈  𝑢 ) ) | 
						
							| 54 | 50 53 | sylan9bbr | ⊢ ( ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  ∧  𝑦  =  ( 𝑢  ∩  𝑌 ) )  →  ( 𝑥  ∈  𝑦  ↔  𝑥  ∈  𝑢 ) ) | 
						
							| 55 |  | vex | ⊢ 𝑠  ∈  V | 
						
							| 56 | 55 | inex1 | ⊢ ( 𝑠  ∩  𝑌 )  ∈  V | 
						
							| 57 | 56 | a1i | ⊢ ( ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  ∧  𝑠  ∈  𝐹 )  →  ( 𝑠  ∩  𝑌 )  ∈  V ) | 
						
							| 58 |  | elrest | ⊢ ( ( 𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  ( 𝑧  ∈  ( 𝐹  ↾t  𝑌 )  ↔  ∃ 𝑠  ∈  𝐹 𝑧  =  ( 𝑠  ∩  𝑌 ) ) ) | 
						
							| 59 | 58 | 3adant1 | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  ( 𝑧  ∈  ( 𝐹  ↾t  𝑌 )  ↔  ∃ 𝑠  ∈  𝐹 𝑧  =  ( 𝑠  ∩  𝑌 ) ) ) | 
						
							| 60 | 59 | adantr | ⊢ ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  →  ( 𝑧  ∈  ( 𝐹  ↾t  𝑌 )  ↔  ∃ 𝑠  ∈  𝐹 𝑧  =  ( 𝑠  ∩  𝑌 ) ) ) | 
						
							| 61 |  | ineq2 | ⊢ ( 𝑧  =  ( 𝑠  ∩  𝑌 )  →  ( 𝑦  ∩  𝑧 )  =  ( 𝑦  ∩  ( 𝑠  ∩  𝑌 ) ) ) | 
						
							| 62 | 61 | adantl | ⊢ ( ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  ∧  𝑧  =  ( 𝑠  ∩  𝑌 ) )  →  ( 𝑦  ∩  𝑧 )  =  ( 𝑦  ∩  ( 𝑠  ∩  𝑌 ) ) ) | 
						
							| 63 | 62 | neeq1d | ⊢ ( ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  ∧  𝑧  =  ( 𝑠  ∩  𝑌 ) )  →  ( ( 𝑦  ∩  𝑧 )  ≠  ∅  ↔  ( 𝑦  ∩  ( 𝑠  ∩  𝑌 ) )  ≠  ∅ ) ) | 
						
							| 64 | 57 60 63 | ralxfr2d | ⊢ ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  →  ( ∀ 𝑧  ∈  ( 𝐹  ↾t  𝑌 ) ( 𝑦  ∩  𝑧 )  ≠  ∅  ↔  ∀ 𝑠  ∈  𝐹 ( 𝑦  ∩  ( 𝑠  ∩  𝑌 ) )  ≠  ∅ ) ) | 
						
							| 65 |  | ineq1 | ⊢ ( 𝑦  =  ( 𝑢  ∩  𝑌 )  →  ( 𝑦  ∩  ( 𝑠  ∩  𝑌 ) )  =  ( ( 𝑢  ∩  𝑌 )  ∩  ( 𝑠  ∩  𝑌 ) ) ) | 
						
							| 66 |  | inindir | ⊢ ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  =  ( ( 𝑢  ∩  𝑌 )  ∩  ( 𝑠  ∩  𝑌 ) ) | 
						
							| 67 | 65 66 | eqtr4di | ⊢ ( 𝑦  =  ( 𝑢  ∩  𝑌 )  →  ( 𝑦  ∩  ( 𝑠  ∩  𝑌 ) )  =  ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 ) ) | 
						
							| 68 | 67 | neeq1d | ⊢ ( 𝑦  =  ( 𝑢  ∩  𝑌 )  →  ( ( 𝑦  ∩  ( 𝑠  ∩  𝑌 ) )  ≠  ∅  ↔  ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  ≠  ∅ ) ) | 
						
							| 69 | 68 | ralbidv | ⊢ ( 𝑦  =  ( 𝑢  ∩  𝑌 )  →  ( ∀ 𝑠  ∈  𝐹 ( 𝑦  ∩  ( 𝑠  ∩  𝑌 ) )  ≠  ∅  ↔  ∀ 𝑠  ∈  𝐹 ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  ≠  ∅ ) ) | 
						
							| 70 | 64 69 | sylan9bb | ⊢ ( ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  ∧  𝑦  =  ( 𝑢  ∩  𝑌 ) )  →  ( ∀ 𝑧  ∈  ( 𝐹  ↾t  𝑌 ) ( 𝑦  ∩  𝑧 )  ≠  ∅  ↔  ∀ 𝑠  ∈  𝐹 ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  ≠  ∅ ) ) | 
						
							| 71 | 54 70 | imbi12d | ⊢ ( ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  ∧  𝑦  =  ( 𝑢  ∩  𝑌 ) )  →  ( ( 𝑥  ∈  𝑦  →  ∀ 𝑧  ∈  ( 𝐹  ↾t  𝑌 ) ( 𝑦  ∩  𝑧 )  ≠  ∅ )  ↔  ( 𝑥  ∈  𝑢  →  ∀ 𝑠  ∈  𝐹 ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  ≠  ∅ ) ) ) | 
						
							| 72 | 46 49 71 | ralxfr2d | ⊢ ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  →  ( ∀ 𝑦  ∈  ( 𝐽  ↾t  𝑌 ) ( 𝑥  ∈  𝑦  →  ∀ 𝑧  ∈  ( 𝐹  ↾t  𝑌 ) ( 𝑦  ∩  𝑧 )  ≠  ∅ )  ↔  ∀ 𝑢  ∈  𝐽 ( 𝑥  ∈  𝑢  →  ∀ 𝑠  ∈  𝐹 ( ( 𝑢  ∩  𝑠 )  ∩  𝑌 )  ≠  ∅ ) ) ) | 
						
							| 73 | 1 | adantr | ⊢ ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  →  𝐽  ∈  ( TopOn ‘ 𝑋 ) ) | 
						
							| 74 | 11 | adantr | ⊢ ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  →  𝐹  ∈  ( Fil ‘ 𝑋 ) ) | 
						
							| 75 | 3 | sselda | ⊢ ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  →  𝑥  ∈  𝑋 ) | 
						
							| 76 |  | fclsopn | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 ) )  →  ( 𝑥  ∈  ( 𝐽  fClus  𝐹 )  ↔  ( 𝑥  ∈  𝑋  ∧  ∀ 𝑢  ∈  𝐽 ( 𝑥  ∈  𝑢  →  ∀ 𝑡  ∈  𝐹 ( 𝑢  ∩  𝑡 )  ≠  ∅ ) ) ) ) | 
						
							| 77 | 76 | baibd | ⊢ ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 ) )  ∧  𝑥  ∈  𝑋 )  →  ( 𝑥  ∈  ( 𝐽  fClus  𝐹 )  ↔  ∀ 𝑢  ∈  𝐽 ( 𝑥  ∈  𝑢  →  ∀ 𝑡  ∈  𝐹 ( 𝑢  ∩  𝑡 )  ≠  ∅ ) ) ) | 
						
							| 78 | 73 74 75 77 | syl21anc | ⊢ ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  →  ( 𝑥  ∈  ( 𝐽  fClus  𝐹 )  ↔  ∀ 𝑢  ∈  𝐽 ( 𝑥  ∈  𝑢  →  ∀ 𝑡  ∈  𝐹 ( 𝑢  ∩  𝑡 )  ≠  ∅ ) ) ) | 
						
							| 79 | 43 72 78 | 3bitr4d | ⊢ ( ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  ∧  𝑥  ∈  𝑌 )  →  ( ∀ 𝑦  ∈  ( 𝐽  ↾t  𝑌 ) ( 𝑥  ∈  𝑦  →  ∀ 𝑧  ∈  ( 𝐹  ↾t  𝑌 ) ( 𝑦  ∩  𝑧 )  ≠  ∅ )  ↔  𝑥  ∈  ( 𝐽  fClus  𝐹 ) ) ) | 
						
							| 80 | 79 | pm5.32da | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  ( ( 𝑥  ∈  𝑌  ∧  ∀ 𝑦  ∈  ( 𝐽  ↾t  𝑌 ) ( 𝑥  ∈  𝑦  →  ∀ 𝑧  ∈  ( 𝐹  ↾t  𝑌 ) ( 𝑦  ∩  𝑧 )  ≠  ∅ ) )  ↔  ( 𝑥  ∈  𝑌  ∧  𝑥  ∈  ( 𝐽  fClus  𝐹 ) ) ) ) | 
						
							| 81 | 16 80 | bitrd | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  ( 𝑥  ∈  ( ( 𝐽  ↾t  𝑌 )  fClus  ( 𝐹  ↾t  𝑌 ) )  ↔  ( 𝑥  ∈  𝑌  ∧  𝑥  ∈  ( 𝐽  fClus  𝐹 ) ) ) ) | 
						
							| 82 |  | elin | ⊢ ( 𝑥  ∈  ( ( 𝐽  fClus  𝐹 )  ∩  𝑌 )  ↔  ( 𝑥  ∈  ( 𝐽  fClus  𝐹 )  ∧  𝑥  ∈  𝑌 ) ) | 
						
							| 83 | 82 | biancomi | ⊢ ( 𝑥  ∈  ( ( 𝐽  fClus  𝐹 )  ∩  𝑌 )  ↔  ( 𝑥  ∈  𝑌  ∧  𝑥  ∈  ( 𝐽  fClus  𝐹 ) ) ) | 
						
							| 84 | 81 83 | bitr4di | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  ( 𝑥  ∈  ( ( 𝐽  ↾t  𝑌 )  fClus  ( 𝐹  ↾t  𝑌 ) )  ↔  𝑥  ∈  ( ( 𝐽  fClus  𝐹 )  ∩  𝑌 ) ) ) | 
						
							| 85 | 84 | eqrdv | ⊢ ( ( 𝐽  ∈  ( TopOn ‘ 𝑋 )  ∧  𝐹  ∈  ( Fil ‘ 𝑋 )  ∧  𝑌  ∈  𝐹 )  →  ( ( 𝐽  ↾t  𝑌 )  fClus  ( 𝐹  ↾t  𝑌 ) )  =  ( ( 𝐽  fClus  𝐹 )  ∩  𝑌 ) ) |