Theorem pm5.74i 178

Description: Distribution of implication over biconditional (inference rule). (Contributed by NM, 1-Aug-1994.)

Hypothesis

Ref	Expression
pm5.74i.1	⊢ (𝜑 → (𝜓 ↔ 𝜒))

Assertion

Ref	Expression
pm5.74i	⊢ ((𝜑 → 𝜓) ↔ (𝜑 → 𝜒))

Proof of Theorem pm5.74i

Step	Hyp	Ref	Expression
1		pm5.74i.1	. 2 ⊢ (𝜑 → (𝜓 ↔ 𝜒))
2		pm5.74 177	. 2 ⊢ ((𝜑 → (𝜓 ↔ 𝜒)) ↔ ((𝜑 → 𝜓) ↔ (𝜑 → 𝜒)))
3	1, 2	mpbi 143	1 ⊢ ((𝜑 → 𝜓) ↔ (𝜑 → 𝜒))

Syntax hints:   → wi 4   ↔ wb 103

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106

This theorem depends on definitions:  df-bi 115

This theorem is referenced by:  bitrd  186  imbi2i  224  bibi2d  230  ibib  243  ibibr  244  anclb  312  pm5.42  313  ancrb  315  equsalh  1655  equsal  1656  sb6a  1906  ralbiia  2381  raaan  3355  isprm4  10645