Nuprl Lemma : eqff_assert_2

∀[b:Decision]. uiff(b = ff ∈ Decision;¬↑b)


Proof




Definitions occuring in Statement :  decision: Decision,  assert: ↑b,  bfalse: ff,  uiff: uiff(P;Q),  uall: ∀[x:A]. B[x],  not: ¬A,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  decision: Decision,  assert: ↑b,  bfalse: ff,  ifthenelse: if b then t else f fi ,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  not: ¬A,  implies: P ⇒ Q,  false: False,  isl: isl(x),  prop: ℙ,  subtype_rel: A ⊆r B,  top: Top,  true: True
Lemmas referenced :  btrue_wf,  bfalse_wf,  and_wf,  equal_wf,  top_wf,  isl_wf,  btrue_neq_bfalse,  true_wf,  it_wf,  unit_wf2,  not_wf,  false_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalHypSubstitution,  unionElimination,  thin,  sqequalRule,  independent_pairFormation,  lambdaFormation,  lemma_by_obid,  hypothesis,  equalitySymmetry,  dependent_set_memberEquality,  equalityTransitivity,  isectElimination,  unionEquality,  hypothesisEquality,  applyEquality,  lambdaEquality,  setElimination,  rename,  productElimination,  setEquality,  independent_functionElimination,  voidElimination,  dependent_functionElimination,  inlEquality,  inrEquality,  isect_memberEquality,  voidEquality,  natural_numberEquality,  because_Cache,  independent_pairEquality,  axiomEquality

Latex:
\mforall{}[b:Decision].  uiff(b  =  ff;\mneg{}\muparrow{}b)



Date html generated: 2016_05_15-PM-01_44_24
Last ObjectModification: 2015_12_27-AM-00_10_37

Theory : basic


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