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SUPPLEMENTARY MATERIAL (USERS' MATHBOXES)
Mathbox for BJ
First-order logic
Nonfreeness
bj-nnf-cbvali
Metamath Proof Explorer
Description: Compared with bj-nnf-cbvaliv , replacing the DV condition on
y , ps with the nonfreeness condition requires ax-11 .
(Contributed by BJ , 4-Apr-2026)
Ref
Expression
Hypotheses
bj-nnf-cbvali.nf0
⊢ ( 𝜑 → ∀ 𝑥 𝜑 )
bj-nnf-cbvali.nf1
⊢ ( 𝜑 → ∀ 𝑦 𝜑 )
bj-nnf-cbvali.ps
⊢ ( 𝜑 → Ⅎ' 𝑦 𝜓 )
bj-nnf-cbvali.ch
⊢ ( 𝜑 → Ⅎ' 𝑥 𝜒 )
bj-nnf-cbvali.is
⊢ ( ( 𝜑 ∧ 𝑥 = 𝑦 ) → ( 𝜓 → 𝜒 ) )
Assertion
bj-nnf-cbvali
⊢ ( 𝜑 → ( ∀ 𝑥 𝜓 → ∀ 𝑦 𝜒 ) )
Proof
Step
Hyp
Ref
Expression
1
bj-nnf-cbvali.nf0
⊢ ( 𝜑 → ∀ 𝑥 𝜑 )
2
bj-nnf-cbvali.nf1
⊢ ( 𝜑 → ∀ 𝑦 𝜑 )
3
bj-nnf-cbvali.ps
⊢ ( 𝜑 → Ⅎ' 𝑦 𝜓 )
4
bj-nnf-cbvali.ch
⊢ ( 𝜑 → Ⅎ' 𝑥 𝜒 )
5
bj-nnf-cbvali.is
⊢ ( ( 𝜑 ∧ 𝑥 = 𝑦 ) → ( 𝜓 → 𝜒 ) )
6
3
bj-nnfad
⊢ ( 𝜑 → ( 𝜓 → ∀ 𝑦 𝜓 ) )
7
1 6
hbald
⊢ ( 𝜑 → ( ∀ 𝑥 𝜓 → ∀ 𝑦 ∀ 𝑥 𝜓 ) )
8
1 4 5
bj-nnf-spim
⊢ ( 𝜑 → ( ∀ 𝑥 𝜓 → 𝜒 ) )
9
2 7 8
bj-alrimd
⊢ ( 𝜑 → ( ∀ 𝑥 𝜓 → ∀ 𝑦 𝜒 ) )