Nuprl Lemma : vdf-eq-firstn-implies

∀[A,B:Type]. ∀[C:A ⟶ B ⟶ Type]. ∀[f:very-dep-fun(A;B;a,b.C[a;b])]. ∀[L:(a:A × b:B × C[a;b]) List]. ∀[j:ℕ||L||].
  (vdf-eq(A;f;firstn(j;L)) ⇒ {∀[i:ℕj]. ((fst(L[i])) = (f firstn(i;L) (fst(snd(L[i])))) ∈ A)})


Proof




Definitions occuring in Statement :  very-dep-fun: very-dep-fun(A;B;a,b.C[a; b]),  vdf-eq: vdf-eq(A;f;L),  firstn: firstn(n;as),  select: L[n],  length: ||as||,  list: T List,  int_seg: {i..j-},  uall: ∀[x:A]. B[x],  guard: {T},  so_apply: x[s1;s2],  pi1: fst(t),  pi2: snd(t),  implies: P ⇒ Q,  apply: f a,  function: x:A ⟶ B[x],  product: x:A × B[x],  natural_number: $n,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  guard: {T},  implies: P ⇒ Q,  so_apply: x[s1;s2],  int_seg: {i..j-},  lelt: i ≤ j < k,  and: P ∧ Q,  less_than: a < b,  squash: ↓T,  subtype_rel: A ⊆r B,  int_iseg: {i...j},  so_lambda: λ2x.t[x],  so_apply: x[s],  prop: ℙ,  uimplies: b supposing a,  all: ∀x:A. B[x],  decidable: Dec(P),  or: P ∨ Q,  not: ¬A,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  le: A ≤ B,  so_lambda: λ2x y.t[x; y],  less_than': less_than'(a;b)
Lemmas referenced :  vdf-eq-implies2,  firstn_wf,  length_firstn,  subtype_rel_sets_simple,  lelt_wf,  length_wf,  le_wf,  decidable__le,  full-omega-unsat,  intformand_wf,  intformnot_wf,  intformle_wf,  itermVar_wf,  intformless_wf,  istype-int,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_var_lemma,  int_formula_prop_less_lemma,  int_formula_prop_wf,  istype-le,  istype-less_than,  int_seg_wf,  vdf-eq_wf,  list_wf,  very-dep-fun_wf,  istype-universe,  subtype_rel_list,  top_wf,  int_seg_subtype_nat,  istype-false,  select-firstn,  firstn-firstn
Rules used in proof :  cut,  introduction,  extract_by_obid,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  hypothesis,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  sqequalRule,  lambdaFormation_alt,  productEquality,  applyEquality,  setElimination,  rename,  productElimination,  imageElimination,  independent_functionElimination,  dependent_set_memberEquality_alt,  independent_pairFormation,  intEquality,  lambdaEquality_alt,  natural_numberEquality,  inhabitedIsType,  independent_isectElimination,  dependent_functionElimination,  unionElimination,  approximateComputation,  dependent_pairFormation_alt,  int_eqEquality,  Error :memTop,  universeIsType,  voidElimination,  productIsType,  because_Cache,  functionIsType,  instantiate,  universeEquality

Latex:
\mforall{}[A,B:Type].  \mforall{}[C:A  {}\mrightarrow{}  B  {}\mrightarrow{}  Type].  \mforall{}[f:very-dep-fun(A;B;a,b.C[a;b])].  \mforall{}[L:(a:A  \mtimes{}  b:B  \mtimes{}  C[a;b])  List].
\mforall{}[j:\mBbbN{}||L||].
    (vdf-eq(A;f;firstn(j;L))  {}\mRightarrow{}  \{\mforall{}[i:\mBbbN{}j].  ((fst(L[i]))  =  (f  firstn(i;L)  (fst(snd(L[i])))))\})



Date html generated: 2020_05_19-PM-09_40_55
Last ObjectModification: 2020_03_06-PM-03_48_10

Theory : co-recursion-2


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