Nuprl Lemma : vdf-wf

[A,B:Type]. ∀[C:A ⟶ B ⟶ Type].
  ∀n:ℕ
    ((vdf(A;B;a,b.C[a;b];n) ∈ Type)
    ∧ (∀f:vdf(A;B;a,b.C[a;b];n). ∀L:(a:A × b:B × C[a;b]) List.  ((||L|| ≤ (n 1))  (vdf-eq(A;f;L) ∈ ℙ))))


Proof




Definitions occuring in Statement :  vdf: vdf(A;B;a,b.C[a; b];n) vdf-eq: vdf-eq(A;f;L) length: ||as|| list: List nat: uall: [x:A]. B[x] prop: so_apply: x[s1;s2] le: A ≤ B all: x:A. B[x] implies:  Q and: P ∧ Q member: t ∈ T function: x:A ⟶ B[x] product: x:A × B[x] add: m natural_number: $n universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T all: x:A. B[x] and: P ∧ Q cand: c∧ B implies:  Q so_apply: x[s1;s2] nat:
Lemmas referenced :  vdf-wf+ istype-le length_wf list_wf istype-nat istype-universe
Rules used in proof :  cut introduction extract_by_obid sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt hypothesis sqequalHypSubstitution isectElimination thin hypothesisEquality lambdaFormation_alt dependent_functionElimination productElimination equalityTransitivity equalitySymmetry independent_pairFormation independent_functionElimination productEquality applyEquality addEquality setElimination rename natural_numberEquality universeIsType functionIsType inhabitedIsType instantiate universeEquality

Latex:
\mforall{}[A,B:Type].  \mforall{}[C:A  {}\mrightarrow{}  B  {}\mrightarrow{}  Type].
    \mforall{}n:\mBbbN{}
        ((vdf(A;B;a,b.C[a;b];n)  \mmember{}  Type)
        \mwedge{}  (\mforall{}f:vdf(A;B;a,b.C[a;b];n).  \mforall{}L:(a:A  \mtimes{}  b:B  \mtimes{}  C[a;b])  List.
                  ((||L||  \mleq{}  (n  +  1))  {}\mRightarrow{}  (vdf-eq(A;f;L)  \mmember{}  \mBbbP{}))))



Date html generated: 2020_05_19-PM-09_40_14
Last ObjectModification: 2020_03_05-PM-04_26_19

Theory : co-recursion-2


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