Nuprl Lemma : case-real2_wf

∀[P:ℙ]. ∀[a,b:ℝ]. ∀[f:a ≠ b ⟶ ((↓P) ∨ (↓¬P))].  (case-real2(a;b;f) ∈ {z:ℝ| (P ⇒ (z = a)) ∧ ((¬P) ⇒ (z = b))} )


Proof




Definitions occuring in Statement :  case-real2: case-real2(a;b;f),  rneq: x ≠ y,  req: x = y,  real: ℝ,  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]} ,  function: x:A ⟶ B[x]
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  case-real2: case-real2(a;b;f),  all: ∀x:A. B[x],  real: ℝ,  nat: ℕ,  le: A ≤ B,  and: P ∧ Q,  less_than': less_than'(a;b),  not: ¬A,  implies: P ⇒ Q,  false: False,  gt: i > j,  or: P ∨ Q,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  uimplies: b supposing a,  ifthenelse: if b then t else f fi ,  rneq: x ≠ y,  rless: x < y,  sq_exists: ∃x:A [B[x]],  prop: ℙ,  bfalse: ff,  exists: ∃x:A. B[x],  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  assert: ↑b,  nat_plus: ℕ+,  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  top: Top,  subtype_rel: A ⊆r B
Lemmas referenced :  case-real_wf,  absval_lbound,  subtract_wf,  istype-void,  istype-le,  lt_int_wf,  eqtt_to_assert,  assert_of_lt_int,  istype-less_than,  rless_wf,  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,  decidable__lt,  full-omega-unsat,  intformand_wf,  intformnot_wf,  intformless_wf,  itermConstant_wf,  itermVar_wf,  istype-int,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_less_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  itermAdd_wf,  intformor_wf,  itermSubtract_wf,  int_term_value_add_lemma,  int_formula_prop_or_lemma,  int_term_value_subtract_lemma,  nat_plus_wf,  absval_wf,  rneq_wf,  squash_wf,  not_wf,  real_wf
Rules used in proof :  cut,  introduction,  extract_by_obid,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  hypothesis,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  lambdaEquality_alt,  setElimination,  rename,  dependent_functionElimination,  applyEquality,  because_Cache,  dependent_set_memberEquality_alt,  natural_numberEquality,  independent_pairFormation,  sqequalRule,  lambdaFormation_alt,  voidElimination,  productElimination,  independent_functionElimination,  addEquality,  inhabitedIsType,  unionElimination,  equalityElimination,  equalityTransitivity,  equalitySymmetry,  independent_isectElimination,  inlEquality_alt,  universeIsType,  dependent_pairFormation_alt,  equalityIstype,  promote_hyp,  instantiate,  cumulativity,  inrEquality_alt,  approximateComputation,  int_eqEquality,  isect_memberEquality_alt,  minusEquality,  setIsType,  functionIsType,  unionIsType,  universeEquality

Latex:
\mforall{}[P:\mBbbP{}].  \mforall{}[a,b:\mBbbR{}].  \mforall{}[f:a  \mneq{}  b  {}\mrightarrow{}  ((\mdownarrow{}P)  \mvee{}  (\mdownarrow{}\mneg{}P))].
    (case-real2(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_59
Last ObjectModification: 2019_05_23-PM-05_48_44

Theory : reals


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