Nuprl Lemma : face_lattice-fset-join-eq-1

∀I:fset(ℕ). ∀s:fset(Point(face_lattice(I))).
  (\/(s) = 1 ∈ Point(face_lattice(I)) ⇐⇒ ∃x:Point(face_lattice(I)). (x ∈ s ∧ (x = 1 ∈ Point(face_lattice(I)))))


Proof




Definitions occuring in Statement :  face_lattice-deq: face_lattice-deq(),  face_lattice: face_lattice(I),  lattice-fset-join: \/(s),  lattice-1: 1,  lattice-point: Point(l),  fset-member: a ∈ s,  fset: fset(T),  nat: ℕ,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  equal: s = t ∈ T
Definitions unfolded in proof :  all: ∀x:A. B[x],  uall: ∀[x:A]. B[x],  member: t ∈ T,  subtype_rel: A ⊆r B,  bdd-distributive-lattice: BoundedDistributiveLattice,  so_lambda: λ2x.t[x],  prop: ℙ,  and: P ∧ Q,  so_apply: x[s],  uimplies: b supposing a,  implies: P ⇒ Q,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  not: ¬A,  false: False,  guard: {T},  exists: ∃x:A. B[x],  squash: ↓T,  true: True,  cand: A c∧ B,  sq_stable: SqStable(P),  decidable: Dec(P),  or: P ∨ Q,  empty-fset: {},  lattice-fset-join: \/(s),  top: Top,  fset-add: fset-add(eq;x;s),  uiff: uiff(P;Q)
Lemmas referenced :  fset-induction,  lattice-point_wf,  face_lattice_wf,  subtype_rel_set,  bounded-lattice-structure_wf,  lattice-structure_wf,  lattice-axioms_wf,  bounded-lattice-structure-subtype,  bounded-lattice-axioms_wf,  uall_wf,  equal_wf,  lattice-meet_wf,  lattice-join_wf,  face_lattice-deq_wf,  iff_wf,  lattice-fset-join_wf,  decidable__equal_face_lattice,  lattice-1_wf,  bdd-distributive-lattice_wf,  exists_wf,  fset-member_wf,  fset_wf,  sq_stable__iff,  sq_stable__equal,  empty-fset_wf,  fset-add_wf,  not_wf,  nat_wf,  squash_wf,  true_wf,  deq_wf,  iff_weakening_equal,  decidable__fset-member,  face-lattice-0-not-1,  reduce_nil_lemma,  member-empty-fset,  bdd-distributive-lattice-subtype-bdd-lattice,  fset-singleton_wf,  face_lattice-1-join-irreducible,  lattice-fset-join-union,  lattice-fset-join-singleton,  fset-union_wf,  member-fset-union,  member-fset-singleton,  or_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  hypothesis,  applyEquality,  sqequalRule,  instantiate,  lambdaEquality,  productEquality,  cumulativity,  universeEquality,  because_Cache,  independent_isectElimination,  dependent_functionElimination,  independent_functionElimination,  setElimination,  rename,  independent_pairFormation,  isect_memberFormation,  voidElimination,  productElimination,  imageElimination,  equalityTransitivity,  equalitySymmetry,  equalityUniverse,  levelHypothesis,  natural_numberEquality,  imageMemberEquality,  baseClosed,  dependent_pairFormation,  unionElimination,  isect_memberEquality,  voidEquality,  inlFormation,  inrFormation,  addLevel,  orFunctionality,  promote_hyp

Latex:
\mforall{}I:fset(\mBbbN{}).  \mforall{}s:fset(Point(face\_lattice(I))).
    (\mbackslash{}/(s)  =  1  \mLeftarrow{}{}\mRightarrow{}  \mexists{}x:Point(face\_lattice(I)).  (x  \mmember{}  s  \mwedge{}  (x  =  1)))



Date html generated: 2017_10_05-AM-01_10_15
Last ObjectModification: 2017_03_02-PM-10_27_18

Theory : cubical!type!theory


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