Definition df-topsp 12669

Description: Define the class of topological spaces (as extensible structures). (Contributed by Stefan O'Rear, 13-Aug-2015.)

Assertion

Ref	Expression
df-topsp	⊢ TopSp = {𝑓 ∣ (TopOpen‘𝑓) ∈ (TopOn‘(Base‘𝑓))}

Detailed syntax breakdown of Definition df-topsp

Step	Hyp	Ref	Expression
1		ctps 12668	. 2 class TopSp
2		vf	. . . . . 6 setvar 𝑓
3	2	cv 1342	. . . . 5 class 𝑓
4		ctopn 12557	. . . . 5 class TopOpen
5	3, 4	cfv 5188	. . . 4 class (TopOpen‘𝑓)
6		cbs 12394	. . . . . 6 class Base
7	3, 6	cfv 5188	. . . . 5 class (Base‘𝑓)
8		ctopon 12648	. . . . 5 class TopOn
9	7, 8	cfv 5188	. . . 4 class (TopOn‘(Base‘𝑓))
10	5, 9	wcel 2136	. . 3 wff (TopOpen‘𝑓) ∈ (TopOn‘(Base‘𝑓))
11	10, 2	cab 2151	. 2 class {𝑓 ∣ (TopOpen‘𝑓) ∈ (TopOn‘(Base‘𝑓))}
12	1, 11	wceq 1343	1 wff TopSp = {𝑓 ∣ (TopOpen‘𝑓) ∈ (TopOn‘(Base‘𝑓))}

This definition is referenced by:  istps  12670