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Description: Technical lemma for bnj852 . This lemma may no longer be used or have become an indirect lemma of the theorem in question (i.e. a lemma of a lemma... of the theorem). (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | bnj579.1 | ⊢ ( 𝜑 ↔ ( 𝑓 ‘ ∅ ) = pred ( 𝑥 , 𝐴 , 𝑅 ) ) | |
| bnj579.2 | ⊢ ( 𝜓 ↔ ∀ 𝑖 ∈ ω ( suc 𝑖 ∈ 𝑛 → ( 𝑓 ‘ suc 𝑖 ) = ∪ 𝑦 ∈ ( 𝑓 ‘ 𝑖 ) pred ( 𝑦 , 𝐴 , 𝑅 ) ) ) | ||
| bnj579.3 | ⊢ 𝐷 = ( ω ∖ { ∅ } ) | ||
| Assertion | bnj579 | ⊢ ( 𝑛 ∈ 𝐷 → ∃* 𝑓 ( 𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | bnj579.1 | ⊢ ( 𝜑 ↔ ( 𝑓 ‘ ∅ ) = pred ( 𝑥 , 𝐴 , 𝑅 ) ) | |
| 2 | bnj579.2 | ⊢ ( 𝜓 ↔ ∀ 𝑖 ∈ ω ( suc 𝑖 ∈ 𝑛 → ( 𝑓 ‘ suc 𝑖 ) = ∪ 𝑦 ∈ ( 𝑓 ‘ 𝑖 ) pred ( 𝑦 , 𝐴 , 𝑅 ) ) ) | |
| 3 | bnj579.3 | ⊢ 𝐷 = ( ω ∖ { ∅ } ) | |
| 4 | biid | ⊢ ( ( 𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓 ) ↔ ( 𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓 ) ) | |
| 5 | biid | ⊢ ( [ 𝑔 / 𝑓 ] 𝜑 ↔ [ 𝑔 / 𝑓 ] 𝜑 ) | |
| 6 | biid | ⊢ ( [ 𝑔 / 𝑓 ] 𝜓 ↔ [ 𝑔 / 𝑓 ] 𝜓 ) | |
| 7 | biid | ⊢ ( [ 𝑔 / 𝑓 ] ( 𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓 ) ↔ [ 𝑔 / 𝑓 ] ( 𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓 ) ) | |
| 8 | biid | ⊢ ( ( ( 𝑛 ∈ 𝐷 ∧ ( 𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓 ) ∧ [ 𝑔 / 𝑓 ] ( 𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓 ) ) → ( 𝑓 ‘ 𝑗 ) = ( 𝑔 ‘ 𝑗 ) ) ↔ ( ( 𝑛 ∈ 𝐷 ∧ ( 𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓 ) ∧ [ 𝑔 / 𝑓 ] ( 𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓 ) ) → ( 𝑓 ‘ 𝑗 ) = ( 𝑔 ‘ 𝑗 ) ) ) | |
| 9 | biid | ⊢ ( ∀ 𝑘 ∈ 𝑛 ( 𝑘 E 𝑗 → [ 𝑘 / 𝑗 ] ( ( 𝑛 ∈ 𝐷 ∧ ( 𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓 ) ∧ [ 𝑔 / 𝑓 ] ( 𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓 ) ) → ( 𝑓 ‘ 𝑗 ) = ( 𝑔 ‘ 𝑗 ) ) ) ↔ ∀ 𝑘 ∈ 𝑛 ( 𝑘 E 𝑗 → [ 𝑘 / 𝑗 ] ( ( 𝑛 ∈ 𝐷 ∧ ( 𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓 ) ∧ [ 𝑔 / 𝑓 ] ( 𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓 ) ) → ( 𝑓 ‘ 𝑗 ) = ( 𝑔 ‘ 𝑗 ) ) ) ) | |
| 10 | 1 2 4 5 6 7 3 8 9 | bnj580 | ⊢ ( 𝑛 ∈ 𝐷 → ∃* 𝑓 ( 𝑓 Fn 𝑛 ∧ 𝜑 ∧ 𝜓 ) ) |