Database
CLASSICAL FIRST-ORDER LOGIC WITH EQUALITY
Propositional calculus
Abbreviated conjunction and disjunction of three wff's
3jaao
Metamath Proof Explorer
Description: Inference conjoining and disjoining the antecedents of three
implications. (Contributed by Jeff Hankins , 15-Aug-2009) (Proof
shortened by Andrew Salmon , 13-May-2011)
Ref
Expression
Hypotheses
3jaao.1
⊢ ( 𝜑 → ( 𝜓 → 𝜒 ) )
3jaao.2
⊢ ( 𝜃 → ( 𝜏 → 𝜒 ) )
3jaao.3
⊢ ( 𝜂 → ( 𝜁 → 𝜒 ) )
Assertion
3jaao
⊢ ( ( 𝜑 ∧ 𝜃 ∧ 𝜂 ) → ( ( 𝜓 ∨ 𝜏 ∨ 𝜁 ) → 𝜒 ) )
Proof
Step
Hyp
Ref
Expression
1
3jaao.1
⊢ ( 𝜑 → ( 𝜓 → 𝜒 ) )
2
3jaao.2
⊢ ( 𝜃 → ( 𝜏 → 𝜒 ) )
3
3jaao.3
⊢ ( 𝜂 → ( 𝜁 → 𝜒 ) )
4
1
3ad2ant1
⊢ ( ( 𝜑 ∧ 𝜃 ∧ 𝜂 ) → ( 𝜓 → 𝜒 ) )
5
2
3ad2ant2
⊢ ( ( 𝜑 ∧ 𝜃 ∧ 𝜂 ) → ( 𝜏 → 𝜒 ) )
6
3
3ad2ant3
⊢ ( ( 𝜑 ∧ 𝜃 ∧ 𝜂 ) → ( 𝜁 → 𝜒 ) )
7
4 5 6
3jaod
⊢ ( ( 𝜑 ∧ 𝜃 ∧ 𝜂 ) → ( ( 𝜓 ∨ 𝜏 ∨ 𝜁 ) → 𝜒 ) )