Description: Omega is equinumerous to a proper subset of itself. Example 13.2(4) of Eisenberg p. 216. (Contributed by NM, 30-Jul-2003)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | omenps | ⊢ ω ≈ ( ω ∖ { ∅ } ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | omex | ⊢ ω ∈ V | |
| 2 | limom | ⊢ Lim ω | |
| 3 | 2 | limenpsi | ⊢ ( ω ∈ V → ω ≈ ( ω ∖ { ∅ } ) ) | 
| 4 | 1 3 | ax-mp | ⊢ ω ≈ ( ω ∖ { ∅ } ) |