| bfol.mm Proof Explorer |
< Previous
Next >
Nearby theorems |
||
| Mirrors > Home > PE Home > Th. List > ax-L6 | |||
| Description: Axiom of Existence.
Note: '𝑥' cannot occur in '𝑡' |
| Ref | Expression |
|---|---|
| ax-L6 | ⊢ ¬ ∀𝑥 ¬ 𝑥 = 𝑡 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | objvar-x | . . . . . 6 objvar 𝑥 | |
| 2 | 1 | term-obj 1 | . . . . 5 term 𝑥 |
| 3 | term-t | . . . . 5 term 𝑡 | |
| 4 | 2, 3 | wff-equals 6 | . . . 4 wff 𝑥 = 𝑡 |
| 5 | 4 | wff-neg 9 | . . 3 wff ¬ 𝑥 = 𝑡 |
| 6 | 5, 1 | wff-forall 8 | . 2 wff ∀𝑥 ¬ 𝑥 = 𝑡 |
| 7 | 6 | wff-neg 9 | 1 wff ¬ ∀𝑥 ¬ 𝑥 = 𝑡 |
| Colors of variables: wff objvar term class |
| This axiom is referenced by: axL6ex-P5 625 |
| Copyright terms: Public domain | W3C validator |