Theorem pm4.45 779

Description: Theorem *4.45 of [WhiteheadRussell] p. 119. (Contributed by NM, 3-Jan-2005.)

Assertion

Ref	Expression
pm4.45	⊢ (𝜑 ↔ (𝜑 ∧ (𝜑 ∨ 𝜓)))

Proof of Theorem pm4.45

Step	Hyp	Ref	Expression
1		orc 707	. 2 ⊢ (𝜑 → (𝜑 ∨ 𝜓))
2	1	pm4.71i 389	1 ⊢ (𝜑 ↔ (𝜑 ∧ (𝜑 ∨ 𝜓)))

Syntax hints:   ∧ wa 103   ↔ wb 104   ∨ wo 703

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 704

This theorem depends on definitions:  df-bi 116

This theorem is referenced by:  dn1dc  955