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

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


Proof




Definitions occuring in Statement :  map: map(f;as) has-value: (a)↓ ifthenelse: if then else fi  bfalse: ff btrue: tt uimplies: supposing a uall: [x:A]. B[x] pi1: fst(t) pi2: snd(t) ispair: if is pair then otherwise b pair: <a, b> base: Base sqequal: t axiom: Ax
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a map: map(f;as) list_ind: list_ind has-value: (a)↓ prop: ifthenelse: if then else fi  all: x:A. B[x] implies:  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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