Nuprl Lemma : sp-lub-is-bottom

∀[A:ℕ ⟶ Sierpinski]. (lub(n.A[n]) = ⊥ ∈ Sierpinski ⇐⇒ ∀n:ℕ. (A[n] = ⊥ ∈ Sierpinski))


Proof




Definitions occuring in Statement :  sp-lub: lub(n.A[n]),  Sierpinski: Sierpinski,  Sierpinski-bottom: ⊥,  nat: ℕ,  uall: ∀[x:A]. B[x],  so_apply: x[s],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  function: x:A ⟶ B[x],  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  all: ∀x:A. B[x],  so_lambda: λ2x.t[x],  so_apply: x[s],  rev_implies: P ⇐ Q,  subtype_rel: A ⊆r B,  uimplies: b supposing a,  nat: ℕ,  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  guard: {T},  Sierpinski: Sierpinski,  prop: ℙ,  rev_uimplies: rev_uimplies(P;Q),  uiff: uiff(P;Q),  cand: A c∧ B,  sp-lub: lub(n.A[n]),  Sierpinski-bottom: ⊥,  quotient: x,y:A//B[x; y],  or: P ∨ Q,  decidable: Dec(P),  false: False,  not: ¬A,  fun-equiv: fun-equiv(X;a,b.E[a; b];f;g),  true: True,  squash: ↓T,  bfalse: ff,  ifthenelse: if b then t else f fi ,  assert: ↑b
Lemmas referenced :  istype-nat,  Sierpinski_wf,  sp-lub_wf,  Sierpinski-bottom_wf,  subtype-Sierpinski,  quotient-function-subtype,  nat_wf,  set_subtype_base,  le_wf,  istype-int,  int_subtype_base,  bool_wf,  iff_wf,  equal-wf-T-base,  two-class-equiv-rel,  fun-equiv-rel,  squash_wf,  equiv_rel_squash,  subtype_rel_self,  quotient_wf,  subtype_rel_transitivity,  fun-equiv_wf,  equal-Sierpinski-bottom,  bfalse_wf,  quotient-member-eq,  istype-assert,  decidable__assert,  assert_wf,  decidable__not,  coded-code-pair,  assert_functionality_wrt_uiff,  coded-pair_wf,  iff_weakening_uiff,  code-pair_wf,  sp-lub_wf1,  equal_wf,  true_wf,  istype-universe,  iff_weakening_equal,  istype-void
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  introduction,  cut,  independent_pairFormation,  lambdaFormation_alt,  hypothesis,  extract_by_obid,  equalityIstype,  universeIsType,  sqequalHypSubstitution,  isectElimination,  thin,  sqequalRule,  lambdaEquality_alt,  applyEquality,  hypothesisEquality,  baseClosed,  sqequalBase,  equalitySymmetry,  functionIsType,  because_Cache,  productElimination,  independent_pairEquality,  dependent_functionElimination,  axiomEquality,  functionIsTypeImplies,  inhabitedIsType,  independent_isectElimination,  intEquality,  natural_numberEquality,  functionEquality,  independent_functionElimination,  closedConclusion,  equalityTransitivity,  equalityIsType4,  equalityIsType1,  productIsType,  equalityIsType3,  pertypeElimination,  pointwiseFunctionalityForEquality,  voidElimination,  unionElimination,  rename,  spreadEquality,  promote_hyp,  imageElimination,  instantiate,  universeEquality,  imageMemberEquality

Latex:
\mforall{}[A:\mBbbN{}  {}\mrightarrow{}  Sierpinski].  (lub(n.A[n])  =  \mbot{}  \mLeftarrow{}{}\mRightarrow{}  \mforall{}n:\mBbbN{}.  (A[n]  =  \mbot{}))



Date html generated: 2019_10_31-AM-06_36_16
Last ObjectModification: 2018_12_13-PM-03_00_18

Theory : synthetic!topology


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