Nuprl Lemma : bag_to_squash_list

∀[T:Type]. ∀[b:bag(T)].  (↓∃L:T List. (b = L ∈ bag(T)))


Proof




Definitions occuring in Statement :  bag: bag(T),  list: T List,  uall: ∀[x:A]. B[x],  exists: ∃x:A. B[x],  squash: ↓T,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  bag: bag(T),  so_lambda: λ2x.t[x],  subtype_rel: A ⊆r B,  uimplies: b supposing a,  so_apply: x[s],  exists: ∃x:A. B[x],  prop: ℙ,  quotient: x,y:A//B[x; y],  and: P ∧ Q,  all: ∀x:A. B[x],  implies: P ⇒ Q,  squash: ↓T
Lemmas referenced :  squash_wf,  exists_wf,  list_wf,  equal_wf,  bag_wf,  list-subtype-bag,  permutation_wf,  equal-wf-base
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalHypSubstitution,  pointwiseFunctionalityForEquality,  extract_by_obid,  isectElimination,  thin,  cumulativity,  hypothesisEquality,  hypothesis,  sqequalRule,  lambdaEquality,  applyEquality,  because_Cache,  independent_isectElimination,  pertypeElimination,  productElimination,  equalityTransitivity,  equalitySymmetry,  lambdaFormation,  rename,  dependent_pairFormation,  imageMemberEquality,  baseClosed,  dependent_functionElimination,  independent_functionElimination,  productEquality,  imageElimination,  isect_memberEquality,  universeEquality

Latex:
\mforall{}[T:Type].  \mforall{}[b:bag(T)].    (\mdownarrow{}\mexists{}L:T  List.  (b  =  L))



Date html generated: 2017_10_01-AM-08_44_54
Last ObjectModification: 2017_07_26-PM-04_30_25

Theory : bags


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