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Definition df-topn 15907
Description: Define the topology extractor function. This differs from df-tset 15787 when a structure has been restricted using df-ress 15702; in this case the TopSet component will still have a topology over the larger set, and this function fixes this by restricting the topology as well. (Contributed by Mario Carneiro, 13-Aug-2015.)
Assertion
Ref Expression
df-topn TopOpen = (𝑤 ∈ V ↦ ((TopSet‘𝑤) ↾t (Base‘𝑤)))

Detailed syntax breakdown of Definition df-topn
StepHypRef Expression
1 ctopn 15905 . 2 class TopOpen
2 vw . . 3 setvar 𝑤
3 cvv 3173 . . 3 class V
42cv 1474 . . . . 5 class 𝑤
5 cts 15774 . . . . 5 class TopSet
64, 5cfv 5804 . . . 4 class (TopSet‘𝑤)
7 cbs 15695 . . . . 5 class Base
84, 7cfv 5804 . . . 4 class (Base‘𝑤)
9 crest 15904 . . . 4 class t
106, 8, 9co 6549 . . 3 class ((TopSet‘𝑤) ↾t (Base‘𝑤))
112, 3, 10cmpt 4643 . 2 class (𝑤 ∈ V ↦ ((TopSet‘𝑤) ↾t (Base‘𝑤)))
121, 11wceq 1475 1 wff TopOpen = (𝑤 ∈ V ↦ ((TopSet‘𝑤) ↾t (Base‘𝑤)))
Colors of variables: wff setvar class
This definition is referenced by:  topnfn  15909  topnval  15918
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