Metamath Proof Explorer


Theorem iscnrm3llem1

Description: Lemma for iscnrm3l . Closed sets in the subspace are subsets of the underlying set of the original topology. (Contributed by Zhi Wang, 4-Sep-2024)

Ref Expression
Assertion iscnrm3llem1 J Top Z 𝒫 J C Clsd J 𝑡 Z D Clsd J 𝑡 Z C D = C 𝒫 J D 𝒫 J

Proof

Step Hyp Ref Expression
1 simp22 J Top Z 𝒫 J C Clsd J 𝑡 Z D Clsd J 𝑡 Z C D = C Clsd J 𝑡 Z
2 simp1 J Top Z 𝒫 J C Clsd J 𝑡 Z D Clsd J 𝑡 Z C D = J Top
3 eqidd J Top Z 𝒫 J C Clsd J 𝑡 Z D Clsd J 𝑡 Z C D = J = J
4 simp21 J Top Z 𝒫 J C Clsd J 𝑡 Z D Clsd J 𝑡 Z C D = Z 𝒫 J
5 4 elpwid J Top Z 𝒫 J C Clsd J 𝑡 Z D Clsd J 𝑡 Z C D = Z J
6 eqidd J Top Z 𝒫 J C Clsd J 𝑡 Z D Clsd J 𝑡 Z C D = J 𝑡 Z = J 𝑡 Z
7 2 3 5 6 1 restcls2lem J Top Z 𝒫 J C Clsd J 𝑡 Z D Clsd J 𝑡 Z C D = C Z
8 7 5 sstrd J Top Z 𝒫 J C Clsd J 𝑡 Z D Clsd J 𝑡 Z C D = C J
9 1 8 elpwd J Top Z 𝒫 J C Clsd J 𝑡 Z D Clsd J 𝑡 Z C D = C 𝒫 J
10 simp23 J Top Z 𝒫 J C Clsd J 𝑡 Z D Clsd J 𝑡 Z C D = D Clsd J 𝑡 Z
11 2 3 5 6 10 restcls2lem J Top Z 𝒫 J C Clsd J 𝑡 Z D Clsd J 𝑡 Z C D = D Z
12 11 5 sstrd J Top Z 𝒫 J C Clsd J 𝑡 Z D Clsd J 𝑡 Z C D = D J
13 10 12 elpwd J Top Z 𝒫 J C Clsd J 𝑡 Z D Clsd J 𝑡 Z C D = D 𝒫 J
14 9 13 jca J Top Z 𝒫 J C Clsd J 𝑡 Z D Clsd J 𝑡 Z C D = C 𝒫 J D 𝒫 J