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:  Q so_apply: x[s1;s2] prop:
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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