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Theorem 3orbi123d 1206
 Description: Deduction joining 3 equivalences to form equivalence of disjunctions. (Contributed by NM, 20-Apr-1994.)
Hypotheses
Ref Expression
bi3d.1
bi3d.2
bi3d.3
Assertion
Ref Expression
3orbi123d

Proof of Theorem 3orbi123d
StepHypRef Expression
1 bi3d.1 . . . 4
2 bi3d.2 . . . 4
31, 2orbi12d 707 . . 3
4 bi3d.3 . . 3
53, 4orbi12d 707 . 2
6 df-3or 886 . 2
7 df-3or 886 . 2
85, 6, 73bitr4g 212 1
 Colors of variables: wff set class Syntax hints:   wi 4   wb 98   wo 629   w3o 884 This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-io 630 This theorem depends on definitions:  df-bi 110  df-3or 886 This theorem is referenced by:  ordtriexmid  4247  wetriext  4301  nntri3or  6072  ltsopi  6418  pitri3or  6420  nqtri3or  6494  elz  8247  ztri3or  8288  qtri3or  9098
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