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Description: G (see om2uz0i ) is an isomorphism from natural ordinals to upper integers. (Contributed by NM, 9-Oct-2008) (Revised by Mario Carneiro, 13-Sep-2013)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | om2uz.1 | ⊢ 𝐶 ∈ ℤ | |
| om2uz.2 | ⊢ 𝐺 = ( rec ( ( 𝑥 ∈ V ↦ ( 𝑥 + 1 ) ) , 𝐶 ) ↾ ω ) | ||
| Assertion | om2uzisoi | ⊢ 𝐺 Isom E , < ( ω , ( ℤ≥ ‘ 𝐶 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | om2uz.1 | ⊢ 𝐶 ∈ ℤ | |
| 2 | om2uz.2 | ⊢ 𝐺 = ( rec ( ( 𝑥 ∈ V ↦ ( 𝑥 + 1 ) ) , 𝐶 ) ↾ ω ) | |
| 3 | 1 2 | om2uzf1oi | ⊢ 𝐺 : ω –1-1-onto→ ( ℤ≥ ‘ 𝐶 ) |
| 4 | epel | ⊢ ( 𝑦 E 𝑧 ↔ 𝑦 ∈ 𝑧 ) | |
| 5 | 1 2 | om2uzlt2i | ⊢ ( ( 𝑦 ∈ ω ∧ 𝑧 ∈ ω ) → ( 𝑦 ∈ 𝑧 ↔ ( 𝐺 ‘ 𝑦 ) < ( 𝐺 ‘ 𝑧 ) ) ) |
| 6 | 4 5 | bitrid | ⊢ ( ( 𝑦 ∈ ω ∧ 𝑧 ∈ ω ) → ( 𝑦 E 𝑧 ↔ ( 𝐺 ‘ 𝑦 ) < ( 𝐺 ‘ 𝑧 ) ) ) |
| 7 | 6 | rgen2 | ⊢ ∀ 𝑦 ∈ ω ∀ 𝑧 ∈ ω ( 𝑦 E 𝑧 ↔ ( 𝐺 ‘ 𝑦 ) < ( 𝐺 ‘ 𝑧 ) ) |
| 8 | df-isom | ⊢ ( 𝐺 Isom E , < ( ω , ( ℤ≥ ‘ 𝐶 ) ) ↔ ( 𝐺 : ω –1-1-onto→ ( ℤ≥ ‘ 𝐶 ) ∧ ∀ 𝑦 ∈ ω ∀ 𝑧 ∈ ω ( 𝑦 E 𝑧 ↔ ( 𝐺 ‘ 𝑦 ) < ( 𝐺 ‘ 𝑧 ) ) ) ) | |
| 9 | 3 7 8 | mpbir2an | ⊢ 𝐺 Isom E , < ( ω , ( ℤ≥ ‘ 𝐶 ) ) |