Theorem anbi2 634

Description: Introduce a left conjunct to both sides of a logical equivalence. (Contributed by NM, 16-Nov-2013.)

Assertion

Ref	Expression
anbi2	⊢ ((𝜑 ↔ 𝜓) → ((𝜒 ∧ 𝜑) ↔ (𝜒 ∧ 𝜓)))

Proof of Theorem anbi2

Step	Hyp	Ref	Expression
1		id 22	. 2 ⊢ ((𝜑 ↔ 𝜓) → (𝜑 ↔ 𝜓))
2	1	anbi2d 630	1 ⊢ ((𝜑 ↔ 𝜓) → ((𝜒 ∧ 𝜑) ↔ (𝜒 ∧ 𝜓)))

Syntax hints:   → wi 4   ↔ wb 206   ∧ wa 395

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem depends on definitions:  df-bi 207  df-an 396

This theorem is referenced by:  eleq2d  2821