Metamath Proof Explorer


Theorem an42ds

Description: Inference exchanging the last antecedent with the second one. See also an32s . (Contributed by Thierry Arnoux, 3-Jun-2025)

Ref Expression
Hypothesis an42ds.1 ( ( ( ( 𝜑𝜓 ) ∧ 𝜒 ) ∧ 𝜃 ) → 𝜏 )
Assertion an42ds ( ( ( ( 𝜑𝜃 ) ∧ 𝜒 ) ∧ 𝜓 ) → 𝜏 )

Proof

Step Hyp Ref Expression
1 an42ds.1 ( ( ( ( 𝜑𝜓 ) ∧ 𝜒 ) ∧ 𝜃 ) → 𝜏 )
2 an32 ( ( ( 𝜑𝜓 ) ∧ 𝜃 ) ↔ ( ( 𝜑𝜃 ) ∧ 𝜓 ) )
3 2 anbi1i ( ( ( ( 𝜑𝜓 ) ∧ 𝜃 ) ∧ 𝜒 ) ↔ ( ( ( 𝜑𝜃 ) ∧ 𝜓 ) ∧ 𝜒 ) )
4 an32 ( ( ( ( 𝜑𝜓 ) ∧ 𝜃 ) ∧ 𝜒 ) ↔ ( ( ( 𝜑𝜓 ) ∧ 𝜒 ) ∧ 𝜃 ) )
5 an32 ( ( ( ( 𝜑𝜃 ) ∧ 𝜓 ) ∧ 𝜒 ) ↔ ( ( ( 𝜑𝜃 ) ∧ 𝜒 ) ∧ 𝜓 ) )
6 3 4 5 3bitr3i ( ( ( ( 𝜑𝜓 ) ∧ 𝜒 ) ∧ 𝜃 ) ↔ ( ( ( 𝜑𝜃 ) ∧ 𝜒 ) ∧ 𝜓 ) )
7 6 1 sylbir ( ( ( ( 𝜑𝜃 ) ∧ 𝜒 ) ∧ 𝜓 ) → 𝜏 )