Nuprl Lemma : bag-null-bag-union

∀[T:Type]. ∀[bbs:bag(bag(T))].  ↑bag-null(bag-union(bbs)) supposing ∀bs:bag(T). (bs ↓∈ bbs ⇒ (↑bag-null(bs)))


Proof




Definitions occuring in Statement :  bag-member: x ↓∈ bs,  bag-union: bag-union(bbs),  bag-null: bag-null(bs),  bag: bag(T),  assert: ↑b,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  implies: P ⇒ Q,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  squash: ↓T,  so_lambda: λ2x.t[x],  implies: P ⇒ Q,  prop: ℙ,  all: ∀x:A. B[x],  so_apply: x[s],  sq_stable: SqStable(P),  exists: ∃x:A. B[x],  subtype_rel: A ⊆r B,  empty-bag: {},  bag-null: bag-null(bs),  null: null(as),  bag-union: bag-union(bbs),  concat: concat(ll),  reduce: reduce(f;k;as),  list_ind: list_ind,  nil: [],  it: ⋅,  btrue: tt,  assert: ↑b,  ifthenelse: if b then t else f fi ,  true: True,  cons-bag: x.b,  top: Top,  guard: {T},  uiff: uiff(P;Q),  and: P ∧ Q,  rev_uimplies: rev_uimplies(P;Q),  cand: A c∧ B,  sq_or: a ↓∨ b,  or: P ∨ Q,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  bag_to_squash_list,  bag_wf,  sq_stable__all,  all_wf,  bag-member_wf,  assert_wf,  bag-null_wf,  bag-union_wf,  sq_stable_from_decidable,  decidable__assert,  assert_witness,  squash_wf,  list_induction,  list-subtype-bag,  subtype_rel_self,  list_wf,  empty-bag_wf,  bag_union_cons_lemma,  assert_functionality_wrt_uiff,  bag-append_wf,  band_wf,  bag-null-append,  cons-bag_wf,  equal-wf-T-base,  assert-bag-null,  bag-member-cons,  iff_transitivity,  iff_weakening_uiff,  assert_of_band,  equal_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  thin,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  cumulativity,  hypothesisEquality,  hypothesis,  imageElimination,  sqequalRule,  lambdaEquality,  functionEquality,  dependent_functionElimination,  independent_functionElimination,  lambdaFormation,  because_Cache,  productElimination,  promote_hyp,  rename,  applyEquality,  independent_isectElimination,  natural_numberEquality,  isect_memberEquality,  voidElimination,  voidEquality,  hyp_replacement,  equalitySymmetry,  Error :applyLambdaEquality,  imageMemberEquality,  baseClosed,  equalityTransitivity,  universeEquality,  productEquality,  independent_pairFormation,  inlFormation,  comment,  inrFormation

Latex:
\mforall{}[T:Type].  \mforall{}[bbs:bag(bag(T))].
    \muparrow{}bag-null(bag-union(bbs))  supposing  \mforall{}bs:bag(T).  (bs  \mdownarrow{}\mmember{}  bbs  {}\mRightarrow{}  (\muparrow{}bag-null(bs)))



Date html generated: 2016_10_25-AM-10_28_50
Last ObjectModification: 2016_07_12-AM-06_45_09

Theory : bags


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