Theorem mpjao3dan 1202

Description: Eliminate a 3-way disjunction in a deduction. (Contributed by Thierry Arnoux, 13-Apr-2018.)

Hypotheses

Ref	Expression
mpjao3dan.1	⊢ ((𝜑 ∧ 𝜓) → 𝜒)
mpjao3dan.2	⊢ ((𝜑 ∧ 𝜃) → 𝜒)
mpjao3dan.3	⊢ ((𝜑 ∧ 𝜏) → 𝜒)
mpjao3dan.4	⊢ (𝜑 → (𝜓 ∨ 𝜃 ∨ 𝜏))

Assertion

Ref	Expression
mpjao3dan	⊢ (𝜑 → 𝜒)

Proof of Theorem mpjao3dan

Step	Hyp	Ref	Expression
1		mpjao3dan.1	. . 3 ⊢ ((𝜑 ∧ 𝜓) → 𝜒)
2		mpjao3dan.2	. . 3 ⊢ ((𝜑 ∧ 𝜃) → 𝜒)
3	1, 2	jaodan 710	. 2 ⊢ ((𝜑 ∧ (𝜓 ∨ 𝜃)) → 𝜒)
4		mpjao3dan.3	. 2 ⊢ ((𝜑 ∧ 𝜏) → 𝜒)
5		mpjao3dan.4	. . 3 ⊢ (𝜑 → (𝜓 ∨ 𝜃 ∨ 𝜏))
6		df-3or 886	. . 3 ⊢ ((𝜓 ∨ 𝜃 ∨ 𝜏) ↔ ((𝜓 ∨ 𝜃) ∨ 𝜏))
7	5, 6	sylib 127	. 2 ⊢ (𝜑 → ((𝜓 ∨ 𝜃) ∨ 𝜏))
8	3, 4, 7	mpjaodan 711	1 ⊢ (𝜑 → 𝜒)

Syntax hints:   → wi 4   ∧ wa 97   ∨ wo 629   ∨ w3o 884

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-io 630

This theorem depends on definitions:  df-bi 110  df-3or 886

This theorem is referenced by:  wetriext  4301  nntri3  6075  nntri2or2  6076  caucvgprlemnkj  6764  caucvgprlemnbj  6765  caucvgprprlemnkj  6790  caucvgprprlemnbj  6791  caucvgsr  6886