Theorem 19.27 2269

Description: Theorem 19.27 of [Margaris] p. 90. See 19.27v 2022 for a version requiring fewer axioms. (Contributed by NM, 21-Jun-1993.)

Hypothesis

Ref	Expression
19.27.1	⊢ Ⅎ𝑥𝜓

Assertion

Ref	Expression
19.27	⊢ (∀𝑥(𝜑 ∧ 𝜓) ↔ (∀𝑥𝜑 ∧ 𝜓))

Proof of Theorem 19.27

Step	Hyp	Ref	Expression
1		19.26 1897	. 2 ⊢ (∀𝑥(𝜑 ∧ 𝜓) ↔ (∀𝑥𝜑 ∧ ∀𝑥𝜓))
2		19.27.1	. . . 4 ⊢ Ⅎ𝑥𝜓
3	2	19.3 2244	. . 3 ⊢ (∀𝑥𝜓 ↔ 𝜓)
4	3	anbi2i 634	. 2 ⊢ ((∀𝑥𝜑 ∧ ∀𝑥𝜓) ↔ (∀𝑥𝜑 ∧ 𝜓))
5	1, 4	bitri 278	1 ⊢ (∀𝑥(𝜑 ∧ 𝜓) ↔ (∀𝑥𝜑 ∧ 𝜓))

Syntax hints:   ↔ wb 209   ∧ wa 400  ∀wal 1565  Ⅎwnf 1810

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1822  ax-4 1836  ax-5 1937  ax-6 1994  ax-7 2035  ax-12 2219

This theorem depends on definitions:  df-bi 210  df-an 401  df-ex 1807  df-nf 1811

This theorem is referenced by: (None)