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Metamath Proof Explorer

Theorem pm1.4

Description: Axiom *1.4 of WhiteheadRussell p. 96. (Contributed by NM, 3-Jan-2005)

		Ref	Expression
	Assertion	pm1.4	⊢ ( ( 𝜑 ∨ 𝜓 ) → ( 𝜓 ∨ 𝜑 ) )

Step	Hyp	Ref	Expression
1		olc	⊢ ( 𝜑 → ( 𝜓 ∨ 𝜑 ) )
2		orc	⊢ ( 𝜓 → ( 𝜓 ∨ 𝜑 ) )
3	1 2	jaoi	⊢ ( ( 𝜑 ∨ 𝜓 ) → ( 𝜓 ∨ 𝜑 ) )