Nuprl Lemma : non-empty-bag-union-of-list

∀[T:Type]. ∀L:bag(T) List. (0 < #(bag-union(L)) ⇐⇒ (∃b∈L. 0 < #(b)))


Proof




Definitions occuring in Statement :  bag-union: bag-union(bbs),  bag-size: #(bs),  bag: bag(T),  l_exists: (∃x∈L. P[x]),  list: T List,  less_than: a < b,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  natural_number: $n,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  member: t ∈ T,  so_lambda: λ2x.t[x],  subtype_rel: A ⊆r B,  uimplies: b supposing a,  nat: ℕ,  prop: ℙ,  so_apply: x[s],  implies: P ⇒ Q,  bag-size: #(bs),  bag-union: bag-union(bbs),  concat: concat(ll),  top: Top,  iff: P ⇐⇒ Q,  and: P ∧ Q,  false: False,  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  rev_implies: P ⇐ Q,  bag-append: as + bs,  or: P ∨ Q,  decidable: Dec(P),  guard: {T},  ge: i ≥ j ,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  not: ¬A,  nat_plus: ℕ+,  uiff: uiff(P;Q)
Lemmas referenced :  list_induction,  bag_wf,  iff_wf,  less_than_wf,  bag-size_wf,  bag-union_wf,  list-subtype-bag,  subtype_rel_self,  nat_wf,  l_exists_wf,  l_member_wf,  list_wf,  reduce_nil_lemma,  length_of_nil_lemma,  false_wf,  l_exists_nil,  l_exists_wf_nil,  reduce_cons_lemma,  bag-size-append,  l_exists_cons,  cons_wf,  or_wf,  decidable__lt,  nat_properties,  satisfiable-full-omega-tt,  intformand_wf,  intformle_wf,  itermConstant_wf,  itermVar_wf,  intformnot_wf,  intformless_wf,  itermAdd_wf,  int_formula_prop_and_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_not_lemma,  int_formula_prop_less_lemma,  int_term_value_add_lemma,  int_formula_prop_wf,  add_nat_plus,  nat_plus_wf,  nat_plus_properties,  add-is-int-iff,  intformeq_wf,  int_formula_prop_eq_lemma,  equal_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  cut,  thin,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  cumulativity,  hypothesisEquality,  hypothesis,  sqequalRule,  lambdaEquality,  natural_numberEquality,  applyEquality,  because_Cache,  independent_isectElimination,  setElimination,  rename,  setEquality,  independent_functionElimination,  dependent_functionElimination,  universeEquality,  isect_memberEquality,  voidElimination,  voidEquality,  independent_pairFormation,  imageElimination,  productElimination,  addLevel,  impliesFunctionality,  addEquality,  equalityTransitivity,  equalitySymmetry,  unionElimination,  applyLambdaEquality,  dependent_pairFormation,  int_eqEquality,  intEquality,  computeAll,  dependent_set_memberEquality,  pointwiseFunctionality,  promote_hyp,  baseApply,  closedConclusion,  baseClosed,  inlFormation,  inrFormation

Latex:
\mforall{}[T:Type].  \mforall{}L:bag(T)  List.  (0  <  \#(bag-union(L))  \mLeftarrow{}{}\mRightarrow{}  (\mexists{}b\mmember{}L.  0  <  \#(b)))



Date html generated: 2017_10_01-AM-08_47_04
Last ObjectModification: 2017_07_26-PM-04_31_44

Theory : bags


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