Metamath Proof Explorer


Theorem starvndxnmulrndx

Description: The slot for the involution function is not the slot for the base set in an extensible structure. Formerly part of proof for ressstarv . (Contributed by AV, 18-Oct-2024)

Ref Expression
Assertion starvndxnmulrndx ( *𝑟 ‘ ndx ) ≠ ( .r ‘ ndx )

Proof

Step Hyp Ref Expression
1 3re 3 ∈ ℝ
2 3lt4 3 < 4
3 1 2 gtneii 4 ≠ 3
4 starvndx ( *𝑟 ‘ ndx ) = 4
5 mulrndx ( .r ‘ ndx ) = 3
6 4 5 neeq12i ( ( *𝑟 ‘ ndx ) ≠ ( .r ‘ ndx ) ↔ 4 ≠ 3 )
7 3 6 mpbir ( *𝑟 ‘ ndx ) ≠ ( .r ‘ ndx )