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 ( ( 𝜑𝜓𝜒 ) ↔ ( ( 𝜑𝜓 ) ∧ 𝜒 ) )

Detailed syntax breakdown

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