Metamath Proof Explorer


Theorem tsetndxnbasendx

Description: The slot for the topology is not the slot for the base set in an extensible structure. (Contributed by AV, 21-Oct-2024)

Ref Expression
Assertion tsetndxnbasendx ( TopSet ‘ ndx ) ≠ ( Base ‘ ndx )

Proof

Step Hyp Ref Expression
1 1re 1 ∈ ℝ
2 1lt9 1 < 9
3 1 2 gtneii 9 ≠ 1
4 tsetndx ( TopSet ‘ ndx ) = 9
5 basendx ( Base ‘ ndx ) = 1
6 4 5 neeq12i ( ( TopSet ‘ ndx ) ≠ ( Base ‘ ndx ) ↔ 9 ≠ 1 )
7 3 6 mpbir ( TopSet ‘ ndx ) ≠ ( Base ‘ ndx )