Theorem 19.26-3an 1905

Description: Theorem 19.26 1903 with triple conjunction. (Contributed by NM, 13-Sep-2011.)

Assertion

Ref	Expression
19.26-3an	⊢ (∀𝑥(𝜑 ∧ 𝜓 ∧ 𝜒) ↔ (∀𝑥𝜑 ∧ ∀𝑥𝜓 ∧ ∀𝑥𝜒))

Proof of Theorem 19.26-3an

Step	Hyp	Ref	Expression
1		19.26 1903	. . 3 ⊢ (∀𝑥(𝜑 ∧ 𝜓) ↔ (∀𝑥𝜑 ∧ ∀𝑥𝜓))
2	1	anbi1i 636	. 2 ⊢ ((∀𝑥(𝜑 ∧ 𝜓) ∧ ∀𝑥𝜒) ↔ ((∀𝑥𝜑 ∧ ∀𝑥𝜓) ∧ ∀𝑥𝜒))
3		df-3an 1105	. . . 4 ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) ↔ ((𝜑 ∧ 𝜓) ∧ 𝜒))
4	3	albii 1852	. . 3 ⊢ (∀𝑥(𝜑 ∧ 𝜓 ∧ 𝜒) ↔ ∀𝑥((𝜑 ∧ 𝜓) ∧ 𝜒))
5		19.26 1903	. . 3 ⊢ (∀𝑥((𝜑 ∧ 𝜓) ∧ 𝜒) ↔ (∀𝑥(𝜑 ∧ 𝜓) ∧ ∀𝑥𝜒))
6	4, 5	bitri 278	. 2 ⊢ (∀𝑥(𝜑 ∧ 𝜓 ∧ 𝜒) ↔ (∀𝑥(𝜑 ∧ 𝜓) ∧ ∀𝑥𝜒))
7		df-3an 1105	. 2 ⊢ ((∀𝑥𝜑 ∧ ∀𝑥𝜓 ∧ ∀𝑥𝜒) ↔ ((∀𝑥𝜑 ∧ ∀𝑥𝜓) ∧ ∀𝑥𝜒))
8	2, 6, 7	3bitr4i 306	1 ⊢ (∀𝑥(𝜑 ∧ 𝜓 ∧ 𝜒) ↔ (∀𝑥𝜑 ∧ ∀𝑥𝜓 ∧ ∀𝑥𝜒))

This proof depends on syntax axioms:   ↔ wb 209   ∧ wa 401   ∧ w3a 1103  ∀wal 1568

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842

This proof depends on definitions:  df-bi 210  df-an 402  df-3an 1105

This theorem is used by:  alrim3con13v  45275  19.21a3con13vVD  45593