Metamath Proof Explorer


Theorem oppgtsetOLD

Description: Obsolete version of oppgtset as of 18-Oct-2024. Topology of an opposite group. (Contributed by Mario Carneiro, 17-Sep-2015) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypotheses oppgbas.1
|- O = ( oppG ` R )
oppgtset.2
|- J = ( TopSet ` R )
Assertion oppgtsetOLD
|- J = ( TopSet ` O )

Proof

Step Hyp Ref Expression
1 oppgbas.1
 |-  O = ( oppG ` R )
2 oppgtset.2
 |-  J = ( TopSet ` R )
3 df-tset
 |-  TopSet = Slot 9
4 9nn
 |-  9 e. NN
5 2re
 |-  2 e. RR
6 2lt9
 |-  2 < 9
7 5 6 gtneii
 |-  9 =/= 2
8 1 3 4 7 oppglemOLD
 |-  ( TopSet ` R ) = ( TopSet ` O )
9 2 8 eqtri
 |-  J = ( TopSet ` O )