Description: Alternate proof of elirrv , shorter but using more axioms. (Contributed by BTernaryTau, 28-Dec-2025) (Proof modification is discouraged.) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | elirrvALT | ⊢ ¬ 𝑥 ∈ 𝑥 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | zfregfr | ⊢ E Fr 𝑥 | |
| 2 | efrirr | ⊢ ( E Fr 𝑥 → ¬ 𝑥 ∈ 𝑥 ) | |
| 3 | 1 2 | ax-mp | ⊢ ¬ 𝑥 ∈ 𝑥 |