Nuprl Lemma : decide2_wf

∀[T1,T2,T3,T4,T5:Type]. ∀[x:T1 + T2]. ∀[y:T3 + T4]. ∀[ll:T1 ⟶ T3 ⟶ T5]. ∀[lr:T1 ⟶ T4 ⟶ T5]. ∀[rl:T2 ⟶ T3 ⟶ T5].
∀[rr:T2 ⟶ T4 ⟶ T5].
  (case x,y
   of inl(a),inl(b) => ll[a;b]
    | inl(a),inr(b) => lr[a;b]
    | inr(a),inl(b) => rl[a;b]
    | inr(a),inr(b) => rr[a;b] ∈ T5)


Proof




Definitions occuring in Statement :  decide2: decide2,  uall: ∀[x:A]. B[x],  so_apply: x[s1;s2],  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,  decide2: decide2,  all: ∀x:A. B[x],  implies: P ⇒ Q,  so_apply: x[s1;s2],  prop: ℙ
Lemmas referenced :  equal_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalRule,  hypothesisEquality,  equalityTransitivity,  hypothesis,  equalitySymmetry,  thin,  because_Cache,  lambdaFormation,  unionElimination,  applyEquality,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  dependent_functionElimination,  independent_functionElimination,  axiomEquality,  functionEquality,  isect_memberEquality,  unionEquality,  universeEquality

Latex:
\mforall{}[T1,T2,T3,T4,T5:Type].  \mforall{}[x:T1  +  T2].  \mforall{}[y:T3  +  T4].  \mforall{}[ll:T1  {}\mrightarrow{}  T3  {}\mrightarrow{}  T5].  \mforall{}[lr:T1  {}\mrightarrow{}  T4  {}\mrightarrow{}  T5].
\mforall{}[rl:T2  {}\mrightarrow{}  T3  {}\mrightarrow{}  T5].  \mforall{}[rr:T2  {}\mrightarrow{}  T4  {}\mrightarrow{}  T5].
    (case  x,y
      of  inl(a),inl(b)  =>  ll[a;b]
        |  inl(a),inr(b)  =>  lr[a;b]
        |  inr(a),inl(b)  =>  rl[a;b]
        |  inr(a),inr(b)  =>  rr[a;b]  \mmember{}  T5)



Date html generated: 2019_10_15-AM-11_14_45
Last ObjectModification: 2018_08_21-PM-01_59_31

Theory : general


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