Nuprl Lemma : fset-ac-glb-is-glb

∀[T:Type]. ∀[eq:EqDecider(T)]. ∀[ac1,ac2:{ac:fset(fset(T))| ↑fset-antichain(eq;ac)} ].
  greatest-lower-bound({ac:fset(fset(T))| ↑fset-antichain(eq;ac)} ;ac1,ac2.fset-ac-le(eq;ac1;ac2);ac1;ac2;fset-ac-glb(eq\000C;ac1;ac2))


Proof




Definitions occuring in Statement :  fset-ac-glb: fset-ac-glb(eq;ac1;ac2),  fset-ac-le: fset-ac-le(eq;ac1;ac2),  fset-antichain: fset-antichain(eq;ac),  fset: fset(T),  deq: EqDecider(T),  greatest-lower-bound: greatest-lower-bound(T;x,y.R[x; y];a;b;c),  assert: ↑b,  uall: ∀[x:A]. B[x],  set: {x:A| B[x]} ,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  greatest-lower-bound: greatest-lower-bound(T;x,y.R[x; y];a;b;c),  and: P ∧ Q,  cand: A c∧ B,  all: ∀x:A. B[x],  implies: P ⇒ Q,  prop: ℙ,  fset-ac-le: fset-ac-le(eq;ac1;ac2),  fset-all: fset-all(s;x.P[x]),  so_lambda: λ2x.t[x],  subtype_rel: A ⊆r B,  so_apply: x[s],  fset-ac-glb: fset-ac-glb(eq;ac1;ac2),  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  uimplies: b supposing a,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q),  not: ¬A,  squash: ↓T,  false: False,  exists: ∃x:A. B[x],  guard: {T},  top: Top,  true: True,  fset-union: x ⋃ y,  l-union: as ⋃ bs,  reduce: reduce(f;k;as),  list_ind: list_ind
Lemmas referenced :  fset-ac-le_wf,  assert_witness,  fset-null_wf,  fset_wf,  fset-filter_wf,  bnot_wf,  deq-f-subset_wf,  fset-ac-glb_wf,  assert_wf,  fset-antichain_wf,  set_wf,  deq_wf,  fset-all-iff,  deq-fset_wf,  iff_weakening_uiff,  fset-all_wf,  fset-minimals_wf,  f-proper-subset-dec_wf,  f-union_wf,  fset-image_wf,  fset-union_wf,  uall_wf,  isect_wf,  fset-member_wf,  assert_of_bnot,  bool_wf,  all_wf,  iff_wf,  f-subset_wf,  member-fset-minimals,  assert-fset-null,  not_wf,  equal-wf-T-base,  member-f-union,  member-fset-image-iff,  member-fset-filter,  assert-deq-f-subset,  f-subset-union,  mem_empty_lemma,  squash_wf,  true_wf,  fset-union-commutes,  iff_weakening_equal,  fset-ac-le_transitivity,  fset-minimals-ac-le,  fset-ac-le-implies,  fset-extensionality,  fset-member_witness,  false_wf,  f-union-subset,  equal_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  independent_pairFormation,  hypothesis,  lambdaFormation,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  cumulativity,  hypothesisEquality,  setElimination,  rename,  because_Cache,  sqequalRule,  productElimination,  independent_pairEquality,  lambdaEquality,  applyEquality,  dependent_set_memberEquality,  independent_functionElimination,  setEquality,  dependent_functionElimination,  isect_memberEquality,  universeEquality,  functionEquality,  functionExtensionality,  independent_isectElimination,  addLevel,  impliesFunctionality,  baseClosed,  equalityTransitivity,  equalitySymmetry,  imageElimination,  hyp_replacement,  applyLambdaEquality,  voidElimination,  voidEquality,  natural_numberEquality,  imageMemberEquality,  dependent_pairFormation,  productEquality

Latex:
\mforall{}[T:Type].  \mforall{}[eq:EqDecider(T)].  \mforall{}[ac1,ac2:\{ac:fset(fset(T))|  \muparrow{}fset-antichain(eq;ac)\}  ].
    greatest-lower-bound(\{ac:fset(fset(T))| 
                                                \muparrow{}fset-antichain(eq;ac)\}  ;ac1,ac2.fset-ac-le(eq;ac1;ac2);ac1;ac2;fset-ac-glb(\000Ceq;ac1;ac2))



Date html generated: 2017_04_17-AM-09_24_17
Last ObjectModification: 2017_02_27-PM-05_27_17

Theory : finite!sets


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