| Step | Hyp | Ref | Expression | 
						
							| 1 |  | eqid | ⊢ ∪  𝐽  =  ∪  𝐽 | 
						
							| 2 | 1 | isfcls | ⊢ ( 𝑥  ∈  ( 𝐽  fClus  𝐹 )  ↔  ( 𝐽  ∈  Top  ∧  𝐹  ∈  ( Fil ‘ ∪  𝐽 )  ∧  ∀ 𝑠  ∈  𝐹 𝑥  ∈  ( ( cls ‘ 𝐽 ) ‘ 𝑠 ) ) ) | 
						
							| 3 | 2 | simp3bi | ⊢ ( 𝑥  ∈  ( 𝐽  fClus  𝐹 )  →  ∀ 𝑠  ∈  𝐹 𝑥  ∈  ( ( cls ‘ 𝐽 ) ‘ 𝑠 ) ) | 
						
							| 4 |  | fveq2 | ⊢ ( 𝑠  =  𝑆  →  ( ( cls ‘ 𝐽 ) ‘ 𝑠 )  =  ( ( cls ‘ 𝐽 ) ‘ 𝑆 ) ) | 
						
							| 5 | 4 | eleq2d | ⊢ ( 𝑠  =  𝑆  →  ( 𝑥  ∈  ( ( cls ‘ 𝐽 ) ‘ 𝑠 )  ↔  𝑥  ∈  ( ( cls ‘ 𝐽 ) ‘ 𝑆 ) ) ) | 
						
							| 6 | 5 | rspcv | ⊢ ( 𝑆  ∈  𝐹  →  ( ∀ 𝑠  ∈  𝐹 𝑥  ∈  ( ( cls ‘ 𝐽 ) ‘ 𝑠 )  →  𝑥  ∈  ( ( cls ‘ 𝐽 ) ‘ 𝑆 ) ) ) | 
						
							| 7 | 3 6 | syl5 | ⊢ ( 𝑆  ∈  𝐹  →  ( 𝑥  ∈  ( 𝐽  fClus  𝐹 )  →  𝑥  ∈  ( ( cls ‘ 𝐽 ) ‘ 𝑆 ) ) ) | 
						
							| 8 | 7 | ssrdv | ⊢ ( 𝑆  ∈  𝐹  →  ( 𝐽  fClus  𝐹 )  ⊆  ( ( cls ‘ 𝐽 ) ‘ 𝑆 ) ) |