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Description: Well-Founded Induction schema, using implicit substitution. (Contributed by Scott Fenton, 24-Aug-2022)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | frpoins2fg.1 | ⊢ ( 𝑦 ∈ 𝐴 → ( ∀ 𝑧 ∈ Pred ( 𝑅 , 𝐴 , 𝑦 ) 𝜓 → 𝜑 ) ) | |
| frpoins2fg.2 | ⊢ Ⅎ 𝑦 𝜓 | ||
| frpoins2fg.3 | ⊢ ( 𝑦 = 𝑧 → ( 𝜑 ↔ 𝜓 ) ) | ||
| Assertion | frpoins2fg | ⊢ ( ( 𝑅 Fr 𝐴 ∧ 𝑅 Po 𝐴 ∧ 𝑅 Se 𝐴 ) → ∀ 𝑦 ∈ 𝐴 𝜑 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | frpoins2fg.1 | ⊢ ( 𝑦 ∈ 𝐴 → ( ∀ 𝑧 ∈ Pred ( 𝑅 , 𝐴 , 𝑦 ) 𝜓 → 𝜑 ) ) | |
| 2 | frpoins2fg.2 | ⊢ Ⅎ 𝑦 𝜓 | |
| 3 | frpoins2fg.3 | ⊢ ( 𝑦 = 𝑧 → ( 𝜑 ↔ 𝜓 ) ) | |
| 4 | sbsbc | ⊢ ( [ 𝑧 / 𝑦 ] 𝜑 ↔ [ 𝑧 / 𝑦 ] 𝜑 ) | |
| 5 | 2 3 | sbiev | ⊢ ( [ 𝑧 / 𝑦 ] 𝜑 ↔ 𝜓 ) |
| 6 | 4 5 | bitr3i | ⊢ ( [ 𝑧 / 𝑦 ] 𝜑 ↔ 𝜓 ) |
| 7 | 6 | ralbii | ⊢ ( ∀ 𝑧 ∈ Pred ( 𝑅 , 𝐴 , 𝑦 ) [ 𝑧 / 𝑦 ] 𝜑 ↔ ∀ 𝑧 ∈ Pred ( 𝑅 , 𝐴 , 𝑦 ) 𝜓 ) |
| 8 | 1 | adantl | ⊢ ( ( ( 𝑅 Fr 𝐴 ∧ 𝑅 Po 𝐴 ∧ 𝑅 Se 𝐴 ) ∧ 𝑦 ∈ 𝐴 ) → ( ∀ 𝑧 ∈ Pred ( 𝑅 , 𝐴 , 𝑦 ) 𝜓 → 𝜑 ) ) |
| 9 | 7 8 | biimtrid | ⊢ ( ( ( 𝑅 Fr 𝐴 ∧ 𝑅 Po 𝐴 ∧ 𝑅 Se 𝐴 ) ∧ 𝑦 ∈ 𝐴 ) → ( ∀ 𝑧 ∈ Pred ( 𝑅 , 𝐴 , 𝑦 ) [ 𝑧 / 𝑦 ] 𝜑 → 𝜑 ) ) |
| 10 | 9 | frpoinsg | ⊢ ( ( 𝑅 Fr 𝐴 ∧ 𝑅 Po 𝐴 ∧ 𝑅 Se 𝐴 ) → ∀ 𝑦 ∈ 𝐴 𝜑 ) |