Theorem orim1i

Description: Introduce disjunct to both sides of an implication. (Contributed by NM, 6-Jun-1994)

	Ref	Expression
Hypothesis	orim1i.1	⊢ ( 𝜑 → 𝜓 )
Assertion	orim1i	⊢ ( ( 𝜑 ∨ 𝜒 ) → ( 𝜓 ∨ 𝜒 ) )

Proof

Step	Hyp	Ref	Expression
1		orim1i.1	⊢ ( 𝜑 → 𝜓 )
2		id	⊢ ( 𝜒 → 𝜒 )
3	1 2	orim12i	⊢ ( ( 𝜑 ∨ 𝜒 ) → ( 𝜓 ∨ 𝜒 ) )