Nuprl Lemma : double-negation-hyp-elim
∀[P,Q:ℙ]. ((P ⇒ (¬Q)) ⇒ (¬¬P) ⇒ (¬Q))
Proof
Definitions occuring in Statement :
uall: ∀[x:A]. B[x],
prop: ℙ,
not: ¬A,
implies: P ⇒ Q
Definitions unfolded in proof :
uall: ∀[x:A]. B[x],
member: t ∈ T,
implies: P ⇒ Q,
not: ¬A,
false: False,
prop: ℙ
Lemmas referenced :
not_wf
Rules used in proof :
sqequalSubstitution,
sqequalTransitivity,
computationStep,
sqequalReflexivity,
isect_memberFormation,
introduction,
cut,
lambdaFormation,
thin,
sqequalHypSubstitution,
hypothesis,
independent_functionElimination,
voidElimination,
hypothesisEquality,
lemma_by_obid,
isectElimination,
functionEquality,
sqequalRule,
lambdaEquality,
dependent_functionElimination,
because_Cache,
universeEquality,
isect_memberEquality
Latex:
\mforall{}[P,Q:\mBbbP{}]. ((P {}\mRightarrow{} (\mneg{}Q)) {}\mRightarrow{} (\mneg{}\mneg{}P) {}\mRightarrow{} (\mneg{}Q))
Date html generated:
2016_05_13-PM-03_46_04
Last ObjectModification:
2015_12_26-AM-09_58_43
Theory : call!by!value_2
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