Nuprl Lemma : lift-simple-decide-decide1

∀[X,F,G,M,N:Top].
  (case case X of inl(x) => inr F[x]  | inr(x) => inl G[x] of inl(a) => M[a] | inr(b) => N[b] ~ case X
   of inl(x) =>
   N[F[x]]
   | inr(x) =>
   M[G[x]])


Proof




Definitions occuring in Statement :  uall: ∀[x:A]. B[x],  top: Top,  so_apply: x[s],  decide: case b of inl(x) => s[x] | inr(y) => t[y],  inr: inr x ,  inl: inl x,  sqequal: s ~ t
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  so_lambda: so_lambda(x,y,z,w.t[x; y; z; w]),  member: t ∈ T,  so_apply: x[s1;s2;s3;s4],  so_lambda: λ2x.t[x],  top: Top,  so_apply: x[s],  uimplies: b supposing a,  strict4: strict4(F),  and: P ∧ Q,  all: ∀x:A. B[x],  implies: P ⇒ Q,  has-value: (a)↓,  prop: ℙ,  guard: {T},  or: P ∨ Q,  squash: ↓T
Lemmas referenced :  lifting-strict-decide,  top_wf,  equal_wf,  has-value_wf_base,  base_wf,  is-exception_wf
Rules used in proof :  sqequalSubstitution,  sqequalRule,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isectElimination,  thin,  baseClosed,  isect_memberEquality,  voidElimination,  voidEquality,  independent_isectElimination,  independent_pairFormation,  lambdaFormation,  callbyvalueDecide,  hypothesis,  hypothesisEquality,  equalityTransitivity,  equalitySymmetry,  unionEquality,  unionElimination,  sqleReflexivity,  dependent_functionElimination,  independent_functionElimination,  baseApply,  closedConclusion,  decideExceptionCases,  inrFormation,  because_Cache,  imageMemberEquality,  imageElimination,  exceptionSqequal,  inlFormation,  isect_memberFormation,  sqequalAxiom

Latex:
\mforall{}[X,F,G,M,N:Top].
    (case  case  X  of  inl(x)  =>  inr  F[x]    |  inr(x)  =>  inl  G[x]  of  inl(a)  =>  M[a]  |  inr(b)  =>  N[b] 
    \msim{}  case  X  of  inl(x)  =>  N[F[x]]  |  inr(x)  =>  M[G[x]])



Date html generated: 2017_10_01-AM-08_39_33
Last ObjectModification: 2017_07_26-PM-04_27_35

Theory : untyped!computation


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