Nuprl Lemma : locally-ranked-is-well-founded

[T:Type]. ∀[R:T ⟶ T ⟶ ℙ].
  (Trans(T;x,y.R[y;x])
   (∀k:ℕ. ∀rank:T ⟶ ℕ. ∀l:T ⟶ ℕk.
        ((∀x,y:T.  (((l x) (l y) ∈ ℤ R[x;y]  rank x < rank y))  tcWO(T;x,y.R[y;x]))))


Proof




Definitions occuring in Statement :  trans: Trans(T;x,y.E[x; y]) tcWO: tcWO(T;x,y.>[x; y]) int_seg: {i..j-} nat: less_than: a < b uall: [x:A]. B[x] prop: so_apply: x[s1;s2] all: x:A. B[x] implies:  Q apply: a function: x:A ⟶ B[x] natural_number: $n int: universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] implies:  Q all: x:A. B[x] tcWO: tcWO(T;x,y.>[x; y]) and: P ∧ Q member: t ∈ T so_apply: x[s1;s2] subtype_rel: A ⊆B squash: T int_seg: {i..j-} so_lambda: λ2x.t[x] nat: so_apply: x[s] uimplies: supposing a prop: so_lambda: λ2y.t[x; y] guard: {T} trans: Trans(T;x,y.E[x; y]) bool: 𝔹 unit: Unit it: btrue: tt ifthenelse: if then else fi  uiff: uiff(P;Q) le: A ≤ B less_than': less_than'(a;b) false: False not: ¬A sq_stable: SqStable(P) lelt: i ≤ j < k bfalse: ff exists: x:A. B[x] or: P ∨ Q sq_type: SQType(T) bnot: ¬bb assert: b subtract: m top: Top true: True ge: i ≥  iff: ⇐⇒ Q rev_implies:  Q less_than: a < b cand: c∧ B
Lemmas referenced :  istype-int set_subtype_base lelt_wf int_subtype_base subtype_rel_self istype-less_than istype-nat int_seg_wf trans_wf istype-universe Dickson's lemma eq_int_wf eqtt_to_assert assert_of_eq_int add_nat_wf istype-false istype-le sq_stable__le eqff_to_assert bool_cases_sqequal subtype_base_sq bool_wf bool_subtype_base assert-bnot neg_assert_of_eq_int int_seg_subtype_nat assert_wf bnot_wf not_wf equal-wf-base istype-assert istype-void istype-sqequal add-is-int-iff le_wf le_antisymmetry_iff condition-implies-le minus-add minus-one-mul zero-add minus-one-mul-top add-commutes add_functionality_wrt_le add-associates add-zero le-add-cancel subtract_wf bool_cases iff_transitivity iff_weakening_uiff assert_of_bnot int_seg_properties nat_properties add-swap less-iff-le le-add-cancel2
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity Error :isect_memberFormation_alt,  Error :lambdaFormation_alt,  independent_pairFormation Error :universeIsType,  cut applyEquality hypothesisEquality hypothesis thin because_Cache sqequalHypSubstitution sqequalRule introduction imageElimination imageMemberEquality baseClosed Error :functionIsType,  Error :equalityIstype,  extract_by_obid isectElimination intEquality Error :lambdaEquality_alt,  natural_numberEquality setElimination rename independent_isectElimination sqequalBase equalitySymmetry instantiate universeEquality Error :inhabitedIsType,  dependent_functionElimination independent_functionElimination unionElimination equalityElimination productElimination Error :dependent_set_memberEquality_alt,  addEquality equalityTransitivity Error :dependent_pairFormation_alt,  promote_hyp cumulativity voidElimination applyLambdaEquality Error :isect_memberEquality_alt,  minusEquality baseApply closedConclusion Error :productIsType

Latex:
\mforall{}[T:Type].  \mforall{}[R:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].
    (Trans(T;x,y.R[y;x])
    {}\mRightarrow{}  (\mforall{}k:\mBbbN{}.  \mforall{}rank:T  {}\mrightarrow{}  \mBbbN{}.  \mforall{}l:T  {}\mrightarrow{}  \mBbbN{}k.
                ((\mforall{}x,y:T.    (((l  x)  =  (l  y))  {}\mRightarrow{}  R[x;y]  {}\mRightarrow{}  rank  x  <  rank  y))  {}\mRightarrow{}  tcWO(T;x,y.R[y;x]))))



Date html generated: 2019_06_20-PM-00_30_10
Last ObjectModification: 2019_01_04-AM-11_46_07

Theory : rel_1


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