Nuprl Lemma : case-real_wf

∀[P:ℙ]. ∀[a,b:ℝ]. ∀[f:{n:ℕ+| 4 < |(a n) - b n|}  ⟶ ((↓P) ∨ (↓¬P))].
  (case-real(a;b;f) ∈ {z:ℝ| (P ⇒ (z = a)) ∧ ((¬P) ⇒ (z = b))} )


Proof




Definitions occuring in Statement :  case-real: case-real(a;b;f),  req: x = y,  real: ℝ,  absval: |i|,  nat_plus: ℕ+,  less_than: a < b,  uall: ∀[x:A]. B[x],  prop: ℙ,  not: ¬A,  squash: ↓T,  implies: P ⇒ Q,  or: P ∨ Q,  and: P ∧ Q,  member: t ∈ T,  set: {x:A| B[x]} ,  apply: f a,  function: x:A ⟶ B[x],  subtract: n - m,  natural_number: $n
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  real: ℝ,  case-real: case-real(a;b;f),  subtype_rel: A ⊆r B,  all: ∀x:A. B[x],  implies: P ⇒ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  nat: ℕ,  band: p ∧b q,  ifthenelse: if b then t else f fi ,  or: P ∨ Q,  bfalse: ff,  exists: ∃x:A. B[x],  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  assert: ↑b,  false: False,  not: ¬A,  rev_implies: P ⇐ Q,  iff: P ⇐⇒ Q,  prop: ℙ,  regular-int-seq: k-regular-seq(f),  squash: ↓T,  nat_plus: ℕ+,  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  top: Top,  rev_uimplies: rev_uimplies(P;Q),  ge: i ≥ j ,  true: True,  so_lambda: λ2x.t[x],  so_apply: x[s],  cand: A c∧ B,  stable: Stable{P},  rneq: x ≠ y,  int_upper: {i...},  le: A ≤ B,  less_than': less_than'(a;b),  gt: i > j,  less_than: a < b,  req: x = y,  bdd-diff: bdd-diff(f;g),  absval: |i|,  subtract: n - m
Lemmas referenced :  lt_int_wf,  absval_wf,  subtract_wf,  eqtt_to_assert,  assert_of_lt_int,  istype-less_than,  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_wf,  squash_wf,  not_wf,  real_wf,  nat_plus_properties,  decidable__le,  full-omega-unsat,  intformand_wf,  intformnot_wf,  intformle_wf,  itermMultiply_wf,  itermConstant_wf,  itermAdd_wf,  itermVar_wf,  intformless_wf,  istype-int,  int_formula_prop_and_lemma,  istype-void,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_mul_lemma,  int_term_value_constant_lemma,  int_term_value_add_lemma,  int_term_value_var_lemma,  int_formula_prop_less_lemma,  int_formula_prop_wf,  le_functionality,  le_weakening,  int-triangle-inequality,  int_subtype_base,  decidable__equal_int,  decidable__lt,  intformeq_wf,  itermSubtract_wf,  int_formula_prop_eq_lemma,  int_term_value_subtract_lemma,  mul_preserves_le,  le_wf,  true_wf,  absval_mul,  subtype_rel_self,  iff_weakening_equal,  nat_wf,  set_subtype_base,  absval-non-neg,  equal_wf,  istype-universe,  left_mul_subtract_distrib,  istype-le,  mul-commutes,  absval_pos,  nat_plus_subtype_nat,  add_functionality_wrt_le,  absval-diff-symmetry,  add-commutes,  accelerate_wf,  regular-int-seq_wf,  real-regular,  req_wf,  stable_req,  false_wf,  minimal-double-negation-hyp-elim,  minimal-not-not-excluded-middle,  req-iff-bdd-diff,  eventually-equal-implies-bdd-diff,  bdd-diff_functionality,  accelerate-bdd-diff,  bdd-diff_weakening,  rneq-iff,  rless-iff4,  absval_lbound,  int_upper_properties,  gt_wf,  istype-int_upper,  subtype_rel_sets_simple,  less_than_transitivity1,  req_functionality,  req_weakening,  istype-false,  minus-one-mul,  add-mul-special,  zero-mul,  le_weakening2
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  introduction,  cut,  sqequalHypSubstitution,  setElimination,  thin,  rename,  lambdaEquality_alt,  extract_by_obid,  isectElimination,  natural_numberEquality,  applyEquality,  hypothesisEquality,  hypothesis,  because_Cache,  sqequalRule,  inhabitedIsType,  lambdaFormation_alt,  unionElimination,  equalityElimination,  equalityTransitivity,  equalitySymmetry,  productElimination,  independent_isectElimination,  dependent_set_memberEquality_alt,  equalityIstype,  dependent_functionElimination,  independent_functionElimination,  dependent_pairFormation_alt,  promote_hyp,  instantiate,  cumulativity,  voidElimination,  universeIsType,  axiomEquality,  functionIsType,  setIsType,  unionIsType,  isect_memberEquality_alt,  isectIsTypeImplies,  universeEquality,  imageElimination,  multiplyEquality,  addEquality,  approximateComputation,  int_eqEquality,  independent_pairFormation,  intEquality,  imageMemberEquality,  baseClosed,  productIsType,  unionEquality,  productEquality,  functionEquality,  inlFormation_alt,  minusEquality,  pointwiseFunctionality,  inrFormation_alt,  sqequalBase

Latex:
\mforall{}[P:\mBbbP{}].  \mforall{}[a,b:\mBbbR{}].  \mforall{}[f:\{n:\mBbbN{}\msupplus{}|  4  <  |(a  n)  -  b  n|\}    {}\mrightarrow{}  ((\mdownarrow{}P)  \mvee{}  (\mdownarrow{}\mneg{}P))].
    (case-real(a;b;f)  \mmember{}  \{z:\mBbbR{}|  (P  {}\mRightarrow{}  (z  =  a))  \mwedge{}  ((\mneg{}P)  {}\mRightarrow{}  (z  =  b))\}  )



Date html generated: 2019_10_29-AM-09_36_43
Last ObjectModification: 2019_05_23-PM-05_35_58

Theory : reals


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