Nuprl Lemma : list-index-cmp-zero

∀[T:Type]. ∀[eq:EqDecider(T)]. ∀[L:T List]. ∀[A:Type]. ∀[f:A ⟶ T]. ∀[x,y:{x:A| (f x ∈ L)} ].
  uiff((list-index-cmp(eq;L;f) x y) = 0 ∈ ℤ;(f x) = (f y) ∈ T)


Proof




Definitions occuring in Statement :  list-index-cmp: list-index-cmp(eq;L;f),  l_member: (x ∈ l),  list: T List,  deq: EqDecider(T),  uiff: uiff(P;Q),  uall: ∀[x:A]. B[x],  set: {x:A| B[x]} ,  apply: f a,  function: x:A ⟶ B[x],  natural_number: $n,  int: ℤ,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  subtype_rel: A ⊆r B,  comparison: comparison(T),  prop: ℙ,  int-minus-comparison: int-minus-comparison(f),  list-index-cmp: list-index-cmp(eq;L;f),  guard: {T},  implies: P ⇒ Q,  all: ∀x:A. B[x],  sq_type: SQType(T),  so_apply: x[s],  so_lambda: λ2x.t[x],  int_seg: {i..j-},  squash: ↓T,  less_than: a < b,  top: Top,  not: ¬A,  false: False,  exists: ∃x:A. B[x],  satisfiable_int_formula: satisfiable_int_formula(fmla),  or: P ∨ Q,  decidable: Dec(P),  lelt: i ≤ j < k,  rev_implies: P ⇐ Q,  iff: P ⇐⇒ Q,  true: True
Lemmas referenced :  list-index-cmp_wf,  int_subtype_base,  l_member_wf,  list_wf,  deq_wf,  list-index-property,  lelt_wf,  set_subtype_base,  length_wf,  int_seg_wf,  subtype_base_sq,  subtract_wf,  equal-wf-T-base,  int_formula_prop_less_lemma,  intformless_wf,  decidable__lt,  int_formula_prop_le_lemma,  intformle_wf,  decidable__le,  int_formula_prop_wf,  int_term_value_constant_lemma,  int_term_value_subtract_lemma,  int_term_value_var_lemma,  int_formula_prop_eq_lemma,  int_formula_prop_not_lemma,  int_formula_prop_and_lemma,  itermConstant_wf,  itermSubtract_wf,  itermVar_wf,  intformeq_wf,  intformnot_wf,  intformand_wf,  satisfiable-full-omega-tt,  decidable__equal_int,  int_seg_properties,  equal_wf,  isl-list-index,  list-index_wf,  top_wf,  outl_wf,  full-omega-unsat,  istype-int,  istype-void,  squash_wf,  true_wf,  subtype_rel_self,  iff_weakening_equal
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :isect_memberFormation_alt,  introduction,  cut,  independent_pairFormation,  hypothesis,  Error :equalityIsType4,  Error :universeIsType,  intEquality,  applyEquality,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  Error :lambdaEquality_alt,  setElimination,  rename,  Error :inhabitedIsType,  equalityTransitivity,  equalitySymmetry,  sqequalRule,  baseClosed,  Error :equalityIsType1,  productElimination,  independent_pairEquality,  Error :isect_memberEquality_alt,  axiomEquality,  Error :isectIsTypeImplies,  Error :setIsType,  Error :functionIsType,  universeEquality,  because_Cache,  independent_isectElimination,  cumulativity,  functionExtensionality,  independent_functionElimination,  dependent_functionElimination,  lambdaEquality,  natural_numberEquality,  instantiate,  imageElimination,  dependent_set_memberEquality,  computeAll,  voidEquality,  voidElimination,  isect_memberEquality,  int_eqEquality,  dependent_pairFormation,  unionElimination,  lambdaFormation,  Error :dependent_set_memberEquality_alt,  closedConclusion,  Error :lambdaFormation_alt,  applyLambdaEquality,  approximateComputation,  Error :dependent_pairFormation_alt,  hyp_replacement,  imageMemberEquality

Latex:
\mforall{}[T:Type].  \mforall{}[eq:EqDecider(T)].  \mforall{}[L:T  List].  \mforall{}[A:Type].  \mforall{}[f:A  {}\mrightarrow{}  T].  \mforall{}[x,y:\{x:A|  (f  x  \mmember{}  L)\}  ].
    uiff((list-index-cmp(eq;L;f)  x  y)  =  0;(f  x)  =  (f  y))



Date html generated: 2019_06_20-PM-01_56_41
Last ObjectModification: 2018_10_15-PM-02_32_50

Theory : decidable!equality


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