Nuprl Lemma : normalize-decide-left

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


Proof




Definitions occuring in Statement :  uall: ∀[x:A]. B[x],  top: Top,  so_apply: x[s],  apply: f a,  decide: case b of inl(x) => s[x] | inr(y) => t[y],  inl: inl x,  sqequal: s ~ t
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  has-value: (a)↓,  all: ∀x:A. B[x],  or: P ∨ Q,  uimplies: b supposing a,  sq_type: SQType(T),  implies: P ⇒ Q,  guard: {T},  uiff: uiff(P;Q),  and: P ∧ Q,  ifthenelse: if b then t else f fi ,  btrue: tt,  bfalse: ff
Lemmas referenced :  assert_of_bnot,  eqff_to_assert,  is-exception_wf,  has-value_wf_base,  eqtt_to_assert,  bool_subtype_base,  bool_wf,  subtype_base_sq,  bool_cases,  top_wf,  isl_wf,  injection-eta
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalSqle,  sqleRule,  thin,  divergentSqle,  callbyvalueDecide,  sqequalHypSubstitution,  hypothesis,  lemma_by_obid,  dependent_functionElimination,  equalityTransitivity,  equalitySymmetry,  isectElimination,  because_Cache,  unionElimination,  instantiate,  cumulativity,  independent_isectElimination,  independent_functionElimination,  productElimination,  sqequalRule,  sqleReflexivity,  baseApply,  closedConclusion,  baseClosed,  hypothesisEquality,  decideExceptionCases,  axiomSqleEquality,  exceptionSqequal,  sqequalAxiom,  isect_memberEquality

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



Date html generated: 2016_05_13-PM-03_43_21
Last ObjectModification: 2016_01_14-PM-07_08_30

Theory : computation


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