Nuprl Lemma : bag-cases

∀[T:Type]. ∀bs:bag(T). ((bs = {} ∈ bag(T)) ∨ (↓∃x:T. ∃bs':bag(T). (bs = ({x} + bs') ∈ bag(T))))


Proof




Definitions occuring in Statement :  bag-append: as + bs,  single-bag: {x},  empty-bag: {},  bag: bag(T),  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  squash: ↓T,  or: P ∨ Q,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  member: t ∈ T,  subtype_rel: A ⊆r B,  nat: ℕ,  decidable: Dec(P),  or: P ∨ Q,  uimplies: b supposing a,  prop: ℙ,  so_lambda: λ2x.t[x],  so_apply: x[s],  guard: {T},  squash: ↓T,  exists: ∃x:A. B[x],  bag-size: #(bs),  satisfiable_int_formula: satisfiable_int_formula(fmla),  top: Top,  false: False,  cons: [a / b],  single-bag: {x},  bag-append: as + bs,  append: as @ bs,  so_lambda: so_lambda(x,y,z.t[x; y; z]),  so_apply: x[s1;s2;s3]
Lemmas referenced :  decidable__le,  bag-size_wf,  nat_wf,  bag-size-zero,  empty-bag_wf,  squash_wf,  exists_wf,  bag_wf,  equal_wf,  bag-append_wf,  single-bag_wf,  bag_to_squash_list,  not_wf,  le_wf,  list-cases,  length_of_nil_lemma,  satisfiable-full-omega-tt,  intformnot_wf,  intformle_wf,  itermConstant_wf,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_formula_prop_wf,  product_subtype_list,  length_of_cons_lemma,  list-subtype-bag,  list_ind_cons_lemma,  list_ind_nil_lemma,  cons_wf,  equal-wf-T-base
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  isectElimination,  cumulativity,  hypothesisEquality,  hypothesis,  applyEquality,  lambdaEquality,  setElimination,  rename,  sqequalRule,  natural_numberEquality,  unionElimination,  inlFormation,  independent_isectElimination,  inrFormation,  imageElimination,  productElimination,  promote_hyp,  equalitySymmetry,  hyp_replacement,  Error :applyLambdaEquality,  because_Cache,  dependent_pairFormation,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  computeAll,  hypothesis_subsumption,  imageMemberEquality,  baseClosed,  universeEquality

Latex:
\mforall{}[T:Type].  \mforall{}bs:bag(T).  ((bs  =  \{\})  \mvee{}  (\mdownarrow{}\mexists{}x:T.  \mexists{}bs':bag(T).  (bs  =  (\{x\}  +  bs'))))



Date html generated: 2016_10_25-AM-10_22_26
Last ObjectModification: 2016_07_12-AM-06_39_07

Theory : bags


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