Nuprl Lemma : or-quotient-true

∀P:ℙ. (⇃(P ∨ (¬P)) ⇒ (⇃(P) ∨ ⇃(¬P)))


Proof




Definitions occuring in Statement :  quotient: x,y:A//B[x; y],  prop: ℙ,  all: ∀x:A. B[x],  not: ¬A,  implies: P ⇒ Q,  or: P ∨ Q,  true: True
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  prop: ℙ,  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  uimplies: b supposing a,  or: P ∨ Q,  quotient: x,y:A//B[x; y],  and: P ∧ Q,  not: ¬A,  false: False,  true: True
Lemmas referenced :  or_wf,  quotient_wf,  true_wf,  equiv_rel_true,  not_wf,  quotient-member-eq,  equal_wf,  equal-wf-base
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  rename,  introduction,  pointwiseFunctionalityForEquality,  cut,  lemma_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  cumulativity,  hypothesisEquality,  sqequalRule,  lambdaEquality,  hypothesis,  because_Cache,  independent_isectElimination,  pertypeElimination,  productElimination,  equalityTransitivity,  equalitySymmetry,  unionElimination,  inlEquality,  dependent_functionElimination,  independent_functionElimination,  voidElimination,  inrEquality,  natural_numberEquality,  productEquality,  universeEquality

Latex:
\mforall{}P:\mBbbP{}.  (\00D9(P  \mvee{}  (\mneg{}P))  {}\mRightarrow{}  (\00D9(P)  \mvee{}  \00D9(\mneg{}P)))



Date html generated: 2016_05_14-AM-06_08_36
Last ObjectModification: 2015_12_26-AM-11_48_17

Theory : quot_1


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