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Mirrors > Home > NFE Home > Th. List > ax-9d1 | GIF version |
Description: Distinct variable version of ax9 1949, equal variables case. (Contributed by Mario Carneiro, 14-Aug-2015.) |
Ref | Expression |
---|---|
ax-9d1 | ⊢ ¬ ∀x ¬ x = x |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | vx | . . . . 5 setvar x | |
2 | 1, 1 | weq 1643 | . . . 4 wff x = x |
3 | 2 | wn 3 | . . 3 wff ¬ x = x |
4 | 3, 1 | wal 1540 | . 2 wff ∀x ¬ x = x |
5 | 4 | wn 3 | 1 wff ¬ ∀x ¬ x = x |
Colors of variables: wff setvar class |
This axiom is referenced by: (None) |
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