Nuprl Lemma : null-bag-size

∀[T:Type]. ∀[x:bag(T)].  (bag-null(x) ~ (#(x) =z 0))


Proof




Definitions occuring in Statement :  bag-size: #(bs),  bag-null: bag-null(bs),  bag: bag(T),  eq_int: (i =z j),  uall: ∀[x:A]. B[x],  natural_number: $n,  universe: Type,  sqequal: s ~ t
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  sq_type: SQType(T),  all: ∀x:A. B[x],  implies: P ⇒ Q,  guard: {T},  subtype_rel: A ⊆r B,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  and: P ∧ Q,  nat: ℕ,  bfalse: ff,  exists: ∃x:A. B[x],  prop: ℙ,  or: P ∨ Q,  bnot: ¬bb,  ifthenelse: if b then t else f fi ,  assert: ↑b,  false: False,  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  not: ¬A,  top: Top,  empty-bag: {},  bag-null: bag-null(bs),  nequal: a ≠ b ∈ T 
Lemmas referenced :  subtype_base_sq,  bool_wf,  bool_subtype_base,  bag_wf,  eq_int_wf,  bag-size_wf,  eqtt_to_assert,  assert_of_eq_int,  nat_wf,  eqff_to_assert,  equal_wf,  bool_cases_sqequal,  assert-bnot,  neg_assert_of_eq_int,  bag-size-zero,  decidable__le,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformle_wf,  itermVar_wf,  itermConstant_wf,  intformeq_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_var_lemma,  int_term_value_constant_lemma,  int_formula_prop_eq_lemma,  int_formula_prop_wf,  null_nil_lemma,  btrue_wf,  bag-null_wf,  assert-bag-null,  equal-wf-T-base,  bfalse_wf,  bag_size_empty_lemma
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  thin,  instantiate,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  cumulativity,  hypothesis,  independent_isectElimination,  dependent_functionElimination,  equalityTransitivity,  equalitySymmetry,  independent_functionElimination,  sqequalAxiom,  hypothesisEquality,  sqequalRule,  isect_memberEquality,  because_Cache,  universeEquality,  applyEquality,  natural_numberEquality,  lambdaFormation,  unionElimination,  equalityElimination,  productElimination,  lambdaEquality,  setElimination,  rename,  dependent_pairFormation,  promote_hyp,  voidElimination,  int_eqEquality,  intEquality,  voidEquality,  independent_pairFormation,  computeAll,  baseClosed,  hyp_replacement,  applyLambdaEquality

Latex:
\mforall{}[T:Type].  \mforall{}[x:bag(T)].    (bag-null(x)  \msim{}  (\#(x)  =\msubz{}  0))



Date html generated: 2017_10_01-AM-08_45_56
Last ObjectModification: 2017_07_26-PM-04_31_01

Theory : bags


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