Nuprl Lemma : decidable__bag-member2

∀[T:Type]. ∀x:T. ((∀y:T. Dec(x = y ∈ T)) ⇒ (∀bs:bag(T). Dec(x ↓∈ bs)))


Proof




Definitions occuring in Statement :  bag-member: x ↓∈ bs,  bag: bag(T),  decidable: Dec(P),  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  implies: P ⇒ Q,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  implies: P ⇒ Q,  decidable: Dec(P),  member: t ∈ T,  prop: ℙ,  subtype_rel: A ⊆r B,  so_lambda: λ2x.t[x],  so_apply: x[s],  or: P ∨ Q,  guard: {T},  not: ¬A,  uimplies: b supposing a,  assert: ↑b,  ifthenelse: if b then t else f fi ,  isl: isl(x),  btrue: tt,  true: True,  bfalse: ff,  false: False,  squash: ↓T,  sq_stable: SqStable(P),  exists: ∃x:A. B[x],  bag-filter: [x∈b|p[x]],  bag-null: bag-null(bs),  uiff: uiff(P;Q),  and: P ∧ Q,  iff: P ⇐⇒ Q
Lemmas referenced :  decidable__assert,  bag-null_wf,  assert_wf,  isl_wf,  equal_wf,  not_wf,  bag-filter_wf,  bag_wf,  all_wf,  decidable_wf,  bag-filter-empty,  or_wf,  bag-member_wf,  bag_to_squash_list,  sq_stable__bag-member,  list-member-bag-member,  assert_of_null,  equal-wf-T-base,  list_wf,  filter_wf5,  l_member_wf,  member_exists,  member_filter,  and_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  rename,  cut,  sqequalHypSubstitution,  sqequalRule,  introduction,  extract_by_obid,  dependent_functionElimination,  thin,  setEquality,  cumulativity,  hypothesisEquality,  isectElimination,  because_Cache,  hypothesis,  applyEquality,  functionExtensionality,  lambdaEquality,  unionElimination,  universeEquality,  inrFormation,  independent_isectElimination,  independent_functionElimination,  natural_numberEquality,  voidElimination,  equalityTransitivity,  equalitySymmetry,  inlFormation,  imageElimination,  productElimination,  promote_hyp,  hyp_replacement,  applyLambdaEquality,  setElimination,  baseClosed,  dependent_set_memberEquality,  independent_pairFormation,  imageMemberEquality

Latex:
\mforall{}[T:Type].  \mforall{}x:T.  ((\mforall{}y:T.  Dec(x  =  y))  {}\mRightarrow{}  (\mforall{}bs:bag(T).  Dec(x  \mdownarrow{}\mmember{}  bs)))



Date html generated: 2018_05_21-PM-09_46_23
Last ObjectModification: 2017_07_26-PM-06_29_59

Theory : bags_2


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