Metamath Proof Explorer


Definition df-3an

Description: Define conjunction ('and') of three wff's. Definition *4.34 of WhiteheadRussell p. 118. This abbreviation reduces the number of parentheses and emphasizes that the order of bracketing is not important by virtue of the associative law anass . (Contributed by NM, 8-Apr-1994)

Ref Expression
Assertion df-3an ( ( 𝜑 ∧ 𝜓 ∧ 𝜒 ) ↔ ( ( 𝜑 ∧ 𝜓 ) ∧ 𝜒 ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 wph ⊢ 𝜑
1 wps ⊢ 𝜓
2 wch ⊢ 𝜒
3 0 1 2 w3a ⊢ ( 𝜑 ∧ 𝜓 ∧ 𝜒 )
4 0 1 wa ⊢ ( 𝜑 ∧ 𝜓 )
5 4 2 wa ⊢ ( ( 𝜑 ∧ 𝜓 ) ∧ 𝜒 )
6 3 5 wb ⊢ ( ( 𝜑 ∧ 𝜓 ∧ 𝜒 ) ↔ ( ( 𝜑 ∧ 𝜓 ) ∧ 𝜒 ) )