Metamath Proof Explorer


Theorem basendxlttsetndx

Description: The index of the slot for the base set is less than the index of the slot for the topology in an extensible structure. (Contributed by AV, 31-Oct-2024)

Ref Expression
Assertion basendxlttsetndx ⊢ Base ndx < TopSet ⁡ ndx

Proof

Step Hyp Ref Expression
1 1lt9 ⊢ 1 < 9
2 basendx ⊢ Base ndx = 1
3 tsetndx ⊢ TopSet ⁡ ndx = 9
4 1 2 3 3brtr4i ⊢ Base ndx < TopSet ⁡ ndx