Nuprl Lemma : decdr-to-bool_wf

∀[T:Type]. ∀[A,B:T ⟶ ℙ]. ∀[d:x:T ⟶ (A[x] + B[x])].  (bool(d) ∈ T ⟶ 𝔹)


Proof




Definitions occuring in Statement :  decdr-to-bool: bool(d),  bool: 𝔹,  uall: ∀[x:A]. B[x],  prop: ℙ,  so_apply: x[s],  member: t ∈ T,  function: x:A ⟶ B[x],  union: left + right,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  so_apply: x[s],  subtype_rel: A ⊆r B,  prop: ℙ,  decdr-to-bool: bool(d),  it: ⋅,  bfalse: ff,  btrue: tt,  ifthenelse: if b then t else f fi ,  all: ∀x:A. B[x],  implies: P ⇒ Q
Lemmas referenced :  subtype_rel_self,  btrue_wf,  bfalse_wf,  equal_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  cut,  sqequalHypSubstitution,  hypothesis,  functionEquality,  hypothesisEquality,  unionEquality,  applyEquality,  thin,  sqequalRule,  instantiate,  introduction,  extract_by_obid,  isectElimination,  because_Cache,  cumulativity,  universeEquality,  lambdaEquality,  lambdaFormation,  equalityTransitivity,  equalitySymmetry,  unionElimination,  dependent_functionElimination,  independent_functionElimination

Latex:
\mforall{}[T:Type].  \mforall{}[A,B:T  {}\mrightarrow{}  \mBbbP{}].  \mforall{}[d:x:T  {}\mrightarrow{}  (A[x]  +  B[x])].    (bool(d)  \mmember{}  T  {}\mrightarrow{}  \mBbbB{})



Date html generated: 2019_10_30-AM-07_36_05
Last ObjectModification: 2018_08_21-PM-02_01_15

Theory : reals


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