Nuprl Lemma : not-not-A-B-example
∀[A,B,F:ℙ].  ((((A ∧ B) ∨ (A 
⇒ F) ∨ (B 
⇒ F)) 
⇒ F) 
⇒ F)
Proof
Definitions occuring in Statement : 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
implies: P 
⇒ Q
, 
or: P ∨ Q
, 
and: P ∧ Q
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
prop: ℙ
, 
or: P ∨ Q
, 
and: P ∧ Q
Lemmas referenced : 
or_wf, 
and_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
hypothesis, 
sqequalHypSubstitution, 
independent_functionElimination, 
thin, 
functionEquality, 
lemma_by_obid, 
isectElimination, 
hypothesisEquality, 
universeEquality, 
inrFormation, 
inlFormation, 
independent_pairFormation
Latex:
\mforall{}[A,B,F:\mBbbP{}].    ((((A  \mwedge{}  B)  \mvee{}  (A  {}\mRightarrow{}  F)  \mvee{}  (B  {}\mRightarrow{}  F))  {}\mRightarrow{}  F)  {}\mRightarrow{}  F)
Date html generated:
2016_05_15-PM-03_19_00
Last ObjectModification:
2015_12_27-PM-01_03_50
Theory : general
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