Metamath Proof Explorer


Theorem orfa1

Description: Add a contradicting disjunct to an antecedent. (Contributed by Giovanni Mascellani, 15-Sep-2017)

Ref Expression
Hypothesis orfa1.1 ⊢ ( 𝜑 → 𝜓 )
Assertion orfa1 ( ( 𝜑 ∨ ⊥ ) → 𝜓 )

Proof

Step Hyp Ref Expression
1 orfa1.1 ⊢ ( 𝜑 → 𝜓 )
2 falim ⊢ ( ⊥ → 𝜓 )
3 1 2 jaoi ⊢ ( ( 𝜑 ∨ ⊥ ) → 𝜓 )