Description: The slot for the topology is not the slot for the involution in an extensible structure. Formerly part of proof for cnfldfunALT . (Contributed by AV, 11-Nov-2024)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | tsetndxnstarvndx | |- ( TopSet ` ndx ) =/= ( *r ` ndx ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | 4re | |- 4 e. RR | |
| 2 | 4lt9 | |- 4 < 9 | |
| 3 | 1 2 | gtneii | |- 9 =/= 4 | 
| 4 | tsetndx | |- ( TopSet ` ndx ) = 9 | |
| 5 | starvndx | |- ( *r ` ndx ) = 4 | |
| 6 | 4 5 | neeq12i | |- ( ( TopSet ` ndx ) =/= ( *r ` ndx ) <-> 9 =/= 4 ) | 
| 7 | 3 6 | mpbir | |- ( TopSet ` ndx ) =/= ( *r ` ndx ) |