Nuprl Lemma : fan-theorem

[X:(𝔹 List) ⟶ ℙ]. (tbar(𝔹;X)  Decidable(X)  (∃k:ℕ. ∀f:ℕ ⟶ 𝔹. ∃n:ℕk. (X map(f;upto(n)))))


Proof




Definitions occuring in Statement :  tbar: tbar(T;X) dec-predicate: Decidable(X) upto: upto(n) map: map(f;as) list: List int_seg: {i..j-} nat: bool: 𝔹 uall: [x:A]. B[x] prop: all: x:A. B[x] exists: x:A. B[x] implies:  Q apply: a function: x:A ⟶ B[x] natural_number: $n
Definitions unfolded in proof :  uall: [x:A]. B[x] implies:  Q member: t ∈ T prop: all: x:A. B[x] sq_exists: x:{A| B[x]} exists: x:A. B[x] so_lambda: λ2x.t[x] nat: int_seg: {i..j-} subtype_rel: A ⊆B so_apply: x[s] uimplies: supposing a le: A ≤ B and: P ∧ Q less_than': less_than'(a;b) false: False not: ¬A uiff: uiff(P;Q) dec-predicate: Decidable(X) decidable: Dec(P) or: P ∨ Q outl: outl(x)
Lemmas referenced :  dec-predicate_wf list_wf bool_wf tbar_wf simple-fan-theorem nat_wf all_wf exists_wf int_seg_wf map_wf subtype_rel_dep_function int_seg_subtype_nat false_wf subtype_rel_self upto_wf not_over_exists not_wf int_seg_decide_wf decidable_wf equal_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation rename cut lemma_by_obid sqequalHypSubstitution isectElimination thin hypothesis hypothesisEquality functionEquality cumulativity universeEquality dependent_functionElimination setElimination dependent_pairFormation sqequalRule lambdaEquality natural_numberEquality applyEquality because_Cache independent_isectElimination independent_pairFormation addLevel impliesFunctionality productElimination independent_functionElimination voidElimination introduction instantiate equalityTransitivity equalitySymmetry unionElimination

Latex:
\mforall{}[X:(\mBbbB{}  List)  {}\mrightarrow{}  \mBbbP{}].  (tbar(\mBbbB{};X)  {}\mRightarrow{}  Decidable(X)  {}\mRightarrow{}  (\mexists{}k:\mBbbN{}.  \mforall{}f:\mBbbN{}  {}\mrightarrow{}  \mBbbB{}.  \mexists{}n:\mBbbN{}k.  (X  map(f;upto(n)))))



Date html generated: 2016_05_15-PM-10_05_18
Last ObjectModification: 2015_12_27-PM-05_51_09

Theory : bar!induction


Home Index