Nuprl Lemma : rat-zero-cases

∀x:ℤ × ℕ+. ((↓r0 ≤ ratreal(x)) ∨ (↓ratreal(x) ≤ r0))


Proof




Definitions occuring in Statement :  ratreal: ratreal(r),  rleq: x ≤ y,  int-to-real: r(n),  nat_plus: ℕ+,  all: ∀x:A. B[x],  squash: ↓T,  or: P ∨ Q,  product: x:A × B[x],  natural_number: $n,  int: ℤ
Definitions unfolded in proof :  all: ∀x:A. B[x],  member: t ∈ T,  subtype_rel: A ⊆r B,  uall: ∀[x:A]. B[x],  or: P ∨ Q,  prop: ℙ,  nat_plus: ℕ+,  decidable: Dec(P),  uimplies: b supposing a,  not: ¬A,  implies: P ⇒ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  top: Top,  false: False,  rat-rleq-cases-ext,  exposed-it: exposed-it,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  and: P ∧ Q,  less_than: a < b,  less_than': less_than'(a;b),  true: True,  squash: ↓T,  bfalse: ff,  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  ifthenelse: if b then t else f fi ,  assert: ↑b,  rev_implies: P ⇐ Q,  iff: P ⇐⇒ Q,  rneq: x ≠ y,  le: A ≤ B
Lemmas referenced :  istype-int,  nat_plus_wf,  rat-rleq-cases-ext,  subtype_rel_self,  squash_wf,  rleq_wf,  ratreal_wf,  decidable__lt,  full-omega-unsat,  intformnot_wf,  intformless_wf,  itermConstant_wf,  int_formula_prop_not_lemma,  istype-void,  int_formula_prop_less_lemma,  int_term_value_constant_lemma,  int_formula_prop_wf,  istype-less_than,  lt_int_wf,  eqtt_to_assert,  assert_of_lt_int,  istype-top,  eqff_to_assert,  bool_cases_sqequal,  subtype_base_sq,  bool_wf,  bool_subtype_base,  assert-bnot,  iff_weakening_uiff,  assert_wf,  less_than_wf,  nat_plus_properties,  intformand_wf,  itermMultiply_wf,  itermVar_wf,  int_formula_prop_and_lemma,  int_term_value_mul_lemma,  int_term_value_var_lemma,  int-to-real_wf,  rdiv_wf,  rless-int,  rless_wf,  rleq-int-fractions2,  istype-false,  rleq_transitivity,  rleq-int-fractions3,  rleq_functionality,  ratreal-req,  req_weakening
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  productIsType,  cut,  introduction,  extract_by_obid,  hypothesis,  universeIsType,  applyEquality,  thin,  instantiate,  sqequalRule,  sqequalHypSubstitution,  isectElimination,  functionEquality,  productEquality,  intEquality,  unionEquality,  hypothesisEquality,  independent_pairEquality,  natural_numberEquality,  dependent_set_memberEquality_alt,  dependent_functionElimination,  unionElimination,  independent_isectElimination,  approximateComputation,  independent_functionElimination,  dependent_pairFormation_alt,  lambdaEquality_alt,  isect_memberEquality_alt,  voidElimination,  productElimination,  multiplyEquality,  setElimination,  rename,  inhabitedIsType,  equalityElimination,  because_Cache,  lessCases,  isect_memberFormation_alt,  axiomSqEquality,  isectIsTypeImplies,  independent_pairFormation,  imageMemberEquality,  baseClosed,  imageElimination,  equalityTransitivity,  equalitySymmetry,  equalityIstype,  promote_hyp,  cumulativity,  int_eqEquality,  inlFormation_alt,  inrFormation_alt,  closedConclusion

Latex:
\mforall{}x:\mBbbZ{}  \mtimes{}  \mBbbN{}\msupplus{}.  ((\mdownarrow{}r0  \mleq{}  ratreal(x))  \mvee{}  (\mdownarrow{}ratreal(x)  \mleq{}  r0))



Date html generated: 2019_10_30-AM-09_29_04
Last ObjectModification: 2019_01_11-AM-11_56_49

Theory : reals


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