Nuprl Lemma : ite_wf

∀[b:𝔹]. ∀[T:Type]. ∀[x:T supposing ↑b]. ∀[y:T supposing ¬↑b].  (ite(b;x;y) ∈ T)


Proof




Definitions occuring in Statement :  ite: ite(b;x;y),  assert: ↑b,  bool: 𝔹,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  not: ¬A,  member: t ∈ T,  universe: Type
Definitions unfolded in proof :  ite: ite(b;x;y),  bool: 𝔹,  assert: ↑b,  ifthenelse: if b then t else f fi ,  member: t ∈ T,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  prop: ℙ,  true: True,  not: ¬A,  implies: P ⇒ Q,  false: False
Lemmas referenced :  not_wf,  assert_wf,  bool_wf,  false_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  sqequalHypSubstitution,  unionElimination,  thin,  sqequalRule,  isectEquality,  cut,  lemma_by_obid,  isectElimination,  hypothesisEquality,  hypothesis,  because_Cache,  universeEquality,  isect_memberFormation,  introduction,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  isect_memberEquality,  independent_isectElimination,  natural_numberEquality,  lambdaEquality,  voidElimination,  lambdaFormation

Latex:
\mforall{}[b:\mBbbB{}].  \mforall{}[T:Type].  \mforall{}[x:T  supposing  \muparrow{}b].  \mforall{}[y:T  supposing  \mneg{}\muparrow{}b].    (ite(b;x;y)  \mmember{}  T)



Date html generated: 2016_05_15-PM-03_26_22
Last ObjectModification: 2015_12_27-PM-01_07_25

Theory : general


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