Theorem pm3.37 679

Description: Theorem *3.37 (Transp) of [WhiteheadRussell] p. 112. (Contributed by NM, 3-Jan-2005.)

Assertion

Ref	Expression
pm3.37	⊢ (((𝜑 ∧ 𝜓) → 𝜒) → ((𝜑 ∧ ¬ 𝜒) → ¬ 𝜓))

Proof of Theorem pm3.37

Step	Hyp	Ref	Expression
1		pm3.3 259	. . 3 ⊢ (((𝜑 ∧ 𝜓) → 𝜒) → (𝜑 → (𝜓 → 𝜒)))
2		con3 632	. . 3 ⊢ ((𝜓 → 𝜒) → (¬ 𝜒 → ¬ 𝜓))
3	1, 2	syl6 33	. 2 ⊢ (((𝜑 ∧ 𝜓) → 𝜒) → (𝜑 → (¬ 𝜒 → ¬ 𝜓)))
4	3	impd 252	1 ⊢ (((𝜑 ∧ 𝜓) → 𝜒) → ((𝜑 ∧ ¬ 𝜒) → ¬ 𝜓))

Syntax hints:  ¬ wn 3   → wi 4   ∧ wa 103

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 604  ax-in2 605

This theorem is referenced by:  ndvdssub  11867