Nuprl Lemma : fset-union-closed

∀[T:Type]. ∀[eq:EqDecider(T)]. ∀[fs:(T ⟶ T) List]. ∀[as,bs:fset(T)].
  ((as ⋃ bs closed under fs)) supposing ((bs closed under fs) and (as closed under fs))


Proof




Definitions occuring in Statement :  fset-closed: (s closed under fs),  fset-union: x ⋃ y,  fset: fset(T),  list: T List,  deq: EqDecider(T),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  fset-closed: (s closed under fs),  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  all: ∀x:A. B[x],  so_lambda: λ2x.t[x],  prop: ℙ,  so_apply: x[s],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  rev_implies: P ⇐ Q,  l_all: (∀x∈L.P[x]),  int_seg: {i..j-},  guard: {T},  lelt: i ≤ j < k,  decidable: Dec(P),  or: P ∨ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  not: ¬A,  top: Top,  less_than: a < b,  squash: ↓T
Lemmas referenced :  member-fset-union,  deq_wf,  list_wf,  fset_wf,  l_all_wf,  int_seg_wf,  int_formula_prop_less_lemma,  intformless_wf,  decidable__lt,  int_formula_prop_wf,  int_term_value_var_lemma,  int_term_value_constant_lemma,  int_formula_prop_le_lemma,  int_formula_prop_not_lemma,  int_formula_prop_and_lemma,  itermVar_wf,  itermConstant_wf,  intformle_wf,  intformnot_wf,  intformand_wf,  satisfiable-full-omega-tt,  decidable__le,  length_wf,  int_seg_properties,  select_wf,  fset-member_witness,  fset-union_wf,  l_member_wf,  fset-member_wf,  isect_wf,  all_wf,  l_all_iff
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  isect_memberFormation,  introduction,  cut,  lemma_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  functionEquality,  hypothesisEquality,  dependent_functionElimination,  lambdaEquality,  hypothesis,  applyEquality,  setElimination,  rename,  setEquality,  productElimination,  independent_functionElimination,  lambdaFormation,  because_Cache,  isect_memberEquality,  cumulativity,  independent_isectElimination,  natural_numberEquality,  unionElimination,  dependent_pairFormation,  int_eqEquality,  intEquality,  voidElimination,  voidEquality,  independent_pairFormation,  computeAll,  imageElimination,  equalityTransitivity,  equalitySymmetry,  universeEquality,  inlFormation,  inrFormation

Latex:
\mforall{}[T:Type].  \mforall{}[eq:EqDecider(T)].  \mforall{}[fs:(T  {}\mrightarrow{}  T)  List].  \mforall{}[as,bs:fset(T)].
    ((as  \mcup{}  bs  closed  under  fs))  supposing  ((bs  closed  under  fs)  and  (as  closed  under  fs))



Date html generated: 2016_05_14-PM-03_44_48
Last ObjectModification: 2016_01_14-PM-10_39_59

Theory : finite!sets


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