Nuprl Lemma : bag-remove1-property1

∀[T:Type]
  ∀eq:EqDecider(T). ∀x:T. ∀L:T List.
    ((∃as,bs:T List. ((L = ((as @ [x]) @ bs) ∈ (T List)) ∧ (bag-remove1(eq;L;x) = (inl (rev(as) @ bs)) ∈ (T List?))))
    ∨ ((¬(x ∈ L)) ∧ (bag-remove1(eq;L;x) = (inr ⋅ ) ∈ (T List?))))


Proof




Definitions occuring in Statement :  bag-remove1: bag-remove1(eq;bs;a),  l_member: (x ∈ l),  reverse: rev(as),  append: as @ bs,  cons: [a / b],  nil: [],  list: T List,  deq: EqDecider(T),  it: ⋅,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  not: ¬A,  or: P ∨ Q,  and: P ∧ Q,  unit: Unit,  inr: inr x ,  inl: inl x,  union: left + right,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  all: ∀x:A. B[x],  bag-remove1: bag-remove1(eq;bs;a),  or: P ∨ Q,  exists: ∃x:A. B[x],  and: P ∧ Q,  subtype_rel: A ⊆r B,  uimplies: b supposing a,  top: Top,  prop: ℙ,  cand: A c∧ B,  so_lambda: λ2x.t[x],  so_apply: x[s],  guard: {T}
Lemmas referenced :  bag_remove1_aux_property,  nil_wf,  append-nil,  reverse_wf,  subtype_rel_list,  top_wf,  equal_wf,  list_wf,  append_wf,  cons_wf,  length_wf,  length-append,  exists_wf,  not_wf,  l_member_wf,  equal-wf-T-base,  unit_wf2,  bag_remove1_aux_wf,  deq_wf
Rules used in proof :  cut,  introduction,  extract_by_obid,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  hypothesis,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  lambdaFormation,  dependent_functionElimination,  cumulativity,  unionElimination,  inlFormation,  productElimination,  dependent_pairFormation,  independent_pairFormation,  promote_hyp,  sqequalRule,  applyEquality,  independent_isectElimination,  lambdaEquality,  isect_memberEquality,  voidElimination,  voidEquality,  because_Cache,  productEquality,  applyLambdaEquality,  unionEquality,  baseClosed,  inrFormation,  universeEquality

Latex:
\mforall{}[T:Type]
    \mforall{}eq:EqDecider(T).  \mforall{}x:T.  \mforall{}L:T  List.
        ((\mexists{}as,bs:T  List.  ((L  =  ((as  @  [x])  @  bs))  \mwedge{}  (bag-remove1(eq;L;x)  =  (inl  (rev(as)  @  bs)))))
        \mvee{}  ((\mneg{}(x  \mmember{}  L))  \mwedge{}  (bag-remove1(eq;L;x)  =  (inr  \mcdot{}  ))))



Date html generated: 2018_05_21-PM-09_48_06
Last ObjectModification: 2017_07_26-PM-06_30_33

Theory : bags_2


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