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Definition df-nei 17117
 Description: Define a function on topologies whose value is a map from a subset to its neighborhoods. (Contributed by NM, 11-Feb-2007.)
Assertion
Ref Expression
df-nei
Distinct variable group:   ,,,

Detailed syntax breakdown of Definition df-nei
StepHypRef Expression
1 cnei 17116 . 2
2 vj . . 3
3 ctop 16913 . . 3
4 vx . . . 4
52cv 1648 . . . . . 6
65cuni 3975 . . . . 5
76cpw 3759 . . . 4
84cv 1648 . . . . . . . 8
9 vg . . . . . . . . 9
109cv 1648 . . . . . . . 8
118, 10wss 3280 . . . . . . 7
12 vy . . . . . . . . 9
1312cv 1648 . . . . . . . 8
1410, 13wss 3280 . . . . . . 7
1511, 14wa 359 . . . . . 6
1615, 9, 5wrex 2667 . . . . 5
1716, 12, 7crab 2670 . . . 4
184, 7, 17cmpt 4226 . . 3
192, 3, 18cmpt 4226 . 2
201, 19wceq 1649 1
 Colors of variables: wff set class This definition is referenced by:  neifval  17118
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