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: List int_seg: {i..j-} uall: [x:A]. B[x] guard: {T} so_apply: x[s1;s2] pi1: fst(t) pi2: snd(t) implies:  Q apply: a function: x:A ⟶ B[x] product: x:A × B[x] natural_number: $n universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T guard: {T} implies:  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 ⊆B int_iseg: {i...j} so_lambda: λ2x.t[x] so_apply: x[s] prop: uimplies: 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: λ2y.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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