Theorem 3ralbii 3141

Description: Inference adding three restricted universal quantifiers to both sides of an equivalence. (Contributed by Peter Mazsa, 25-Jul-2019.)

Hypothesis

Ref	Expression
3ralbii.1	⊢ (𝜑 ↔ 𝜓)

Assertion

Ref	Expression
3ralbii	⊢ (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐵 ∀𝑧 ∈ 𝐶 𝜑 ↔ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐵 ∀𝑧 ∈ 𝐶 𝜓)

Proof of Theorem 3ralbii

Step	Hyp	Ref	Expression
1		3ralbii.1	. . 3 ⊢ (𝜑 ↔ 𝜓)
2	1	2ralbii 3139	. 2 ⊢ (∀𝑦 ∈ 𝐵 ∀𝑧 ∈ 𝐶 𝜑 ↔ ∀𝑦 ∈ 𝐵 ∀𝑧 ∈ 𝐶 𝜓)
3	2	ralbii 3110	1 ⊢ (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐵 ∀𝑧 ∈ 𝐶 𝜑 ↔ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐵 ∀𝑧 ∈ 𝐶 𝜓)

This proof depends on syntax axioms:   ↔ wb 209  ∀wral 3078

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1824  ax-4 1838

This proof depends on definitions:  df-bi 210  df-ral 3079

This theorem is used by:  4ralbii  3142  cbvral4vw  3249  isdomn4r  20828  usgrexmpl2trifr  48830