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Theorem dedt 767
Description: The weak deduction theorem. For more information, see the Deduction Theorem link on the Metamath Proof Explorer home page.
Hypotheses
Ref Expression
dedt.1 |- ((ph <-> ((ph /\ ch) \/ (ps /\ -. ch))) -> (th <-> ta))
dedt.2 |- ta
Assertion
Ref Expression
dedt |- (ch -> th)

Proof of Theorem dedt
StepHypRef Expression
1 dedlema 764 . 2 |- (ch -> (ph <-> ((ph /\ ch) \/ (ps /\ -. ch))))
2 dedt.2 . . 3 |- ta
3 dedt.1 . . 3 |- ((ph <-> ((ph /\ ch) \/ (ps /\ -. ch))) -> (th <-> ta))
42, 3mpbiri 194 . 2 |- ((ph <-> ((ph /\ ch) \/ (ps /\ -. ch))) -> th)
51, 4syl 10 1 |- (ch -> th)
Colors of variables: wff set class
Syntax hints:  -. wn 2   -> wi 3   <-> wb 146   \/ wo 222   /\ wa 223
This theorem is referenced by:  con3th 768
This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7
This theorem depends on definitions:  df-bi 147  df-or 224  df-an 225
Copyright terms: Public domain