Metamath Proof Explorer


Definition df-bnj17

Description: Define the 4-way conjunction. (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)

Ref Expression
Assertion df-bnj17 ( ( 𝜑𝜓𝜒𝜃 ) ↔ ( ( 𝜑𝜓𝜒 ) ∧ 𝜃 ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 wph 𝜑
1 wps 𝜓
2 wch 𝜒
3 wth 𝜃
4 0 1 2 3 w-bnj17 ( 𝜑𝜓𝜒𝜃 )
5 0 1 2 w3a ( 𝜑𝜓𝜒 )
6 5 3 wa ( ( 𝜑𝜓𝜒 ) ∧ 𝜃 )
7 4 6 wb ( ( 𝜑𝜓𝜒𝜃 ) ↔ ( ( 𝜑𝜓𝜒 ) ∧ 𝜃 ) )