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Theorem 3orass 937
Description: Associative law for triple disjunction. (Contributed by NM, 8-Apr-1994.)
Assertion
Ref Expression
3orass ((φ ψ χ) ↔ (φ (ψ χ)))

Proof of Theorem 3orass
StepHypRef Expression
1 df-3or 935 . 2 ((φ ψ χ) ↔ ((φ ψ) χ))
2 orass 510 . 2 (((φ ψ) χ) ↔ (φ (ψ χ)))
31, 2bitri 240 1 ((φ ψ χ) ↔ (φ (ψ χ)))
Colors of variables: wff setvar class
Syntax hints:  wb 176   wo 357   w3o 933
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8
This theorem depends on definitions:  df-bi 177  df-or 359  df-3or 935
This theorem is referenced by:  3orrot  940  3orcoma  942  3orcomb  944  3mix1  1124  ecase23d  1285  cador  1391  moeq3  3013  lenltfin  4469
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