Nuprl Lemma : not-not-p-or-not-p

∀P,A:ℙ.  (((P ∨ (P ⇒ A)) ⇒ A) ⇒ A)


Proof




Definitions occuring in Statement :  prop: ℙ,  all: ∀x:A. B[x],  implies: P ⇒ Q,  or: P ∨ Q
Definitions unfolded in proof :  or: P ∨ Q,  guard: {T},  uall: ∀[x:A]. B[x],  prop: ℙ,  member: t ∈ T,  implies: P ⇒ Q,  all: ∀x:A. B[x]
Lemmas referenced :  or_wf
Rules used in proof :  because_Cache,  inlFormation,  inrFormation,  sqequalRule,  independent_functionElimination,  universeEquality,  hypothesisEquality,  thin,  isectElimination,  sqequalHypSubstitution,  extract_by_obid,  introduction,  functionEquality,  levelHypothesis,  addLevel,  hypothesis,  cut,  lambdaFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution

Latex:
\mforall{}P,A:\mBbbP{}.    (((P  \mvee{}  (P  {}\mRightarrow{}  A))  {}\mRightarrow{}  A)  {}\mRightarrow{}  A)



Date html generated: 2016_10_21-AM-09_35_18
Last ObjectModification: 2016_09_23-PM-04_22_40

Theory : core_2


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