Nuprl Lemma : decomp-map-if-has-value

∀[t,f:Base].  if ispair(t) then t ~ <fst(t), snd(t)> else t ~ Ax fi  supposing (map(f;t))↓


Proof




Definitions occuring in Statement :  map: map(f;as),  has-value: (a)↓,  ifthenelse: if b then t else f fi ,  bfalse: ff,  btrue: tt,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  pi1: fst(t),  pi2: snd(t),  ispair: if z is a pair then a otherwise b,  pair: <a, b>,  base: Base,  sqequal: s ~ t,  axiom: Ax
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  map: map(f;as),  list_ind: list_ind,  has-value: (a)↓,  prop: ℙ,  ifthenelse: if b then t else f fi ,  all: ∀x:A. B[x],  implies: P ⇒ Q,  bool: 𝔹,  or: P ∨ Q,  pi1: fst(t),  pi2: snd(t),  btrue: tt,  bfalse: ff,  not: ¬A,  false: False
Lemmas referenced :  has-value-if-has-value-map,  ispair-bool-if-has-value,  has-value_wf_base,  base_wf,  equal_wf,  bool_wf,  has-value-implies-dec-ispair,  has-value-implies-dec-isaxiom,  bottom_diverge
Rules used in proof :  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isectElimination,  thin,  hypothesisEquality,  independent_isectElimination,  hypothesis,  sqequalRule,  callbyvalueCallbyvalue,  callbyvalueReduce,  because_Cache,  sqequalIntensionalEquality,  baseApply,  closedConclusion,  baseClosed,  instantiate,  isect_memberFormation,  lambdaFormation,  unionElimination,  sqequalAxiom,  equalityTransitivity,  equalitySymmetry,  dependent_functionElimination,  independent_functionElimination,  isect_memberEquality,  voidElimination

Latex:
\mforall{}[t,f:Base].    if  ispair(t)  then  t  \msim{}  <fst(t),  snd(t)>  else  t  \msim{}  Ax  fi    supposing  (map(f;t))\mdownarrow{}



Date html generated: 2018_05_21-PM-10_19_16
Last ObjectModification: 2017_07_26-PM-06_36_54

Theory : eval!all


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