Metamath Proof Explorer


Theorem bnj1186

Description: Technical lemma for bnj69 . 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 bnj1186.1 𝑧𝑤 ( ( 𝜑𝜓 ) → ( 𝑧𝐵 ∧ ( 𝑤𝐵 → ¬ 𝑤 𝑅 𝑧 ) ) )
Assertion bnj1186 ( ( 𝜑𝜓 ) → ∃ 𝑧𝐵𝑤𝐵 ¬ 𝑤 𝑅 𝑧 )

Proof

Step Hyp Ref Expression
1 bnj1186.1 𝑧𝑤 ( ( 𝜑𝜓 ) → ( 𝑧𝐵 ∧ ( 𝑤𝐵 → ¬ 𝑤 𝑅 𝑧 ) ) )
2 19.21v ( ∀ 𝑤 ( ( 𝜑𝜓 ) → ( 𝑧𝐵 ∧ ( 𝑤𝐵 → ¬ 𝑤 𝑅 𝑧 ) ) ) ↔ ( ( 𝜑𝜓 ) → ∀ 𝑤 ( 𝑧𝐵 ∧ ( 𝑤𝐵 → ¬ 𝑤 𝑅 𝑧 ) ) ) )
3 2 exbii ( ∃ 𝑧𝑤 ( ( 𝜑𝜓 ) → ( 𝑧𝐵 ∧ ( 𝑤𝐵 → ¬ 𝑤 𝑅 𝑧 ) ) ) ↔ ∃ 𝑧 ( ( 𝜑𝜓 ) → ∀ 𝑤 ( 𝑧𝐵 ∧ ( 𝑤𝐵 → ¬ 𝑤 𝑅 𝑧 ) ) ) )
4 1 3 mpbi 𝑧 ( ( 𝜑𝜓 ) → ∀ 𝑤 ( 𝑧𝐵 ∧ ( 𝑤𝐵 → ¬ 𝑤 𝑅 𝑧 ) ) )
5 4 19.37iv ( ( 𝜑𝜓 ) → ∃ 𝑧𝑤 ( 𝑧𝐵 ∧ ( 𝑤𝐵 → ¬ 𝑤 𝑅 𝑧 ) ) )
6 19.28v ( ∀ 𝑤 ( 𝑧𝐵 ∧ ( 𝑤𝐵 → ¬ 𝑤 𝑅 𝑧 ) ) ↔ ( 𝑧𝐵 ∧ ∀ 𝑤 ( 𝑤𝐵 → ¬ 𝑤 𝑅 𝑧 ) ) )
7 6 exbii ( ∃ 𝑧𝑤 ( 𝑧𝐵 ∧ ( 𝑤𝐵 → ¬ 𝑤 𝑅 𝑧 ) ) ↔ ∃ 𝑧 ( 𝑧𝐵 ∧ ∀ 𝑤 ( 𝑤𝐵 → ¬ 𝑤 𝑅 𝑧 ) ) )
8 5 7 sylib ( ( 𝜑𝜓 ) → ∃ 𝑧 ( 𝑧𝐵 ∧ ∀ 𝑤 ( 𝑤𝐵 → ¬ 𝑤 𝑅 𝑧 ) ) )
9 df-ral ( ∀ 𝑤𝐵 ¬ 𝑤 𝑅 𝑧 ↔ ∀ 𝑤 ( 𝑤𝐵 → ¬ 𝑤 𝑅 𝑧 ) )
10 9 anbi2i ( ( 𝑧𝐵 ∧ ∀ 𝑤𝐵 ¬ 𝑤 𝑅 𝑧 ) ↔ ( 𝑧𝐵 ∧ ∀ 𝑤 ( 𝑤𝐵 → ¬ 𝑤 𝑅 𝑧 ) ) )
11 10 exbii ( ∃ 𝑧 ( 𝑧𝐵 ∧ ∀ 𝑤𝐵 ¬ 𝑤 𝑅 𝑧 ) ↔ ∃ 𝑧 ( 𝑧𝐵 ∧ ∀ 𝑤 ( 𝑤𝐵 → ¬ 𝑤 𝑅 𝑧 ) ) )
12 8 11 sylibr ( ( 𝜑𝜓 ) → ∃ 𝑧 ( 𝑧𝐵 ∧ ∀ 𝑤𝐵 ¬ 𝑤 𝑅 𝑧 ) )
13 df-rex ( ∃ 𝑧𝐵𝑤𝐵 ¬ 𝑤 𝑅 𝑧 ↔ ∃ 𝑧 ( 𝑧𝐵 ∧ ∀ 𝑤𝐵 ¬ 𝑤 𝑅 𝑧 ) )
14 12 13 sylibr ( ( 𝜑𝜓 ) → ∃ 𝑧𝐵𝑤𝐵 ¬ 𝑤 𝑅 𝑧 )