Theorem nfe2

Description: An inner existential quantifier's variable is bound. (Contributed by SN, 11-Feb-2026)

	Ref	Expression
Assertion	nfe2	⊢ Ⅎ 𝑥 ∃ 𝑦 ∃ 𝑥 𝜑

Proof

Step	Hyp	Ref	Expression
1		excom	⊢ ( ∃ 𝑦 ∃ 𝑥 𝜑 ↔ ∃ 𝑥 ∃ 𝑦 𝜑 )
2		nfe1	⊢ Ⅎ 𝑥 ∃ 𝑥 ∃ 𝑦 𝜑
3	1 2	nfxfr	⊢ Ⅎ 𝑥 ∃ 𝑦 ∃ 𝑥 𝜑