Nuprl Lemma : vdf-eq-implies

∀[A,B:Type]. ∀[C:A ⟶ B ⟶ Type]. ∀[n:ℕ]. ∀[f:vdf(A;B;a,b.C[a;b];n)]. ∀[L:(a:A × b:B × C[a;b]) List].
  vdf-eq(A;f;L) ⇒ (∀[i:ℕ||L||]. ((fst(L[i])) = (f firstn(i;L) (fst(snd(L[i])))) ∈ A)) supposing ||L|| ≤ (n + 1)


Proof




Definitions occuring in Statement :  vdf: vdf(A;B;a,b.C[a; b];n),  vdf-eq: vdf-eq(A;f;L),  firstn: firstn(n;as),  select: L[n],  length: ||as||,  list: T List,  int_seg: {i..j-},  nat: ℕ,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  so_apply: x[s1;s2],  pi1: fst(t),  pi2: snd(t),  le: A ≤ B,  implies: P ⇒ Q,  apply: f a,  function: x:A ⟶ B[x],  product: x:A × B[x],  add: n + m,  natural_number: $n,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  all: ∀x:A. B[x],  and: P ∧ Q,  uimplies: b supposing a,  implies: P ⇒ Q,  subtype_rel: A ⊆r B,  prop: ℙ,  so_apply: x[s1;s2],  nat: ℕ
Lemmas referenced :  vdf-wf+,  istype-le,  length_wf,  list_wf,  istype-universe
Rules used in proof :  cut,  introduction,  extract_by_obid,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  hypothesis,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  dependent_functionElimination,  productElimination,  independent_functionElimination,  equalityTransitivity,  equalitySymmetry,  lambdaFormation_alt,  rename,  applyEquality,  sqequalRule,  universeIsType,  productEquality,  addEquality,  setElimination,  natural_numberEquality,  isect_memberEquality_alt,  lambdaEquality_alt,  axiomEquality,  isectIsTypeImplies,  inhabitedIsType,  functionIsTypeImplies,  because_Cache,  functionIsType,  instantiate,  universeEquality

Latex:
\mforall{}[A,B:Type].  \mforall{}[C:A  {}\mrightarrow{}  B  {}\mrightarrow{}  Type].  \mforall{}[n:\mBbbN{}].  \mforall{}[f:vdf(A;B;a,b.C[a;b];n)].
\mforall{}[L:(a:A  \mtimes{}  b:B  \mtimes{}  C[a;b])  List].
    vdf-eq(A;f;L)  {}\mRightarrow{}  (\mforall{}[i:\mBbbN{}||L||].  ((fst(L[i]))  =  (f  firstn(i;L)  (fst(snd(L[i])))))) 
    supposing  ||L||  \mleq{}  (n  +  1)



Date html generated: 2020_05_19-PM-09_40_51
Last ObjectModification: 2020_03_05-PM-04_49_08

Theory : co-recursion-2


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