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Description: Technical lemma for bnj150 . 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 | ||
|---|---|---|---|
| Hypothesis | bnj96.1 | ⊢ 𝐹 = { 〈 ∅ , pred ( 𝑥 , 𝐴 , 𝑅 ) 〉 } | |
| Assertion | bnj97 | ⊢ ( ( 𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴 ) → ( 𝐹 ‘ ∅ ) = pred ( 𝑥 , 𝐴 , 𝑅 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | bnj96.1 | ⊢ 𝐹 = { 〈 ∅ , pred ( 𝑥 , 𝐴 , 𝑅 ) 〉 } | |
| 2 | bnj93 | ⊢ ( ( 𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴 ) → pred ( 𝑥 , 𝐴 , 𝑅 ) ∈ V ) | |
| 3 | 0ex | ⊢ ∅ ∈ V | |
| 4 | 3 | bnj519 | ⊢ ( pred ( 𝑥 , 𝐴 , 𝑅 ) ∈ V → Fun { 〈 ∅ , pred ( 𝑥 , 𝐴 , 𝑅 ) 〉 } ) |
| 5 | 1 | funeqi | ⊢ ( Fun 𝐹 ↔ Fun { 〈 ∅ , pred ( 𝑥 , 𝐴 , 𝑅 ) 〉 } ) |
| 6 | 4 5 | sylibr | ⊢ ( pred ( 𝑥 , 𝐴 , 𝑅 ) ∈ V → Fun 𝐹 ) |
| 7 | 2 6 | syl | ⊢ ( ( 𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴 ) → Fun 𝐹 ) |
| 8 | opex | ⊢ 〈 ∅ , pred ( 𝑥 , 𝐴 , 𝑅 ) 〉 ∈ V | |
| 9 | 8 | snid | ⊢ 〈 ∅ , pred ( 𝑥 , 𝐴 , 𝑅 ) 〉 ∈ { 〈 ∅ , pred ( 𝑥 , 𝐴 , 𝑅 ) 〉 } |
| 10 | 9 1 | eleqtrri | ⊢ 〈 ∅ , pred ( 𝑥 , 𝐴 , 𝑅 ) 〉 ∈ 𝐹 |
| 11 | funopfv | ⊢ ( Fun 𝐹 → ( 〈 ∅ , pred ( 𝑥 , 𝐴 , 𝑅 ) 〉 ∈ 𝐹 → ( 𝐹 ‘ ∅ ) = pred ( 𝑥 , 𝐴 , 𝑅 ) ) ) | |
| 12 | 7 10 11 | mpisyl | ⊢ ( ( 𝑅 FrSe 𝐴 ∧ 𝑥 ∈ 𝐴 ) → ( 𝐹 ‘ ∅ ) = pred ( 𝑥 , 𝐴 , 𝑅 ) ) |