Nuprl Lemma : decidable__exists_length_bool

[P:(𝔹 List) ⟶ ℙ]. ((∀L:𝔹 List. Dec(P[L]))  (∀n:ℕDec(∃L:𝔹 List. ((||L|| n ∈ ℤ) ∧ P[L]))))


Proof




Definitions occuring in Statement :  length: ||as|| list: List nat: bool: 𝔹 decidable: Dec(P) uall: [x:A]. B[x] prop: so_apply: x[s] all: x:A. B[x] exists: x:A. B[x] implies:  Q and: P ∧ Q function: x:A ⟶ B[x] int: equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T implies:  Q exists: x:A. B[x] nat: le: A ≤ B and: P ∧ Q less_than': less_than'(a;b) false: False not: ¬A prop: so_lambda: λ2x.t[x] so_apply: x[s]
Lemmas referenced :  decidable__exists_length bool_wf false_wf le_wf equipollent-two equipollent_wf int_seg_wf all_wf list_wf decidable_wf
Rules used in proof :  cut lemma_by_obid sqequalHypSubstitution sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isectElimination thin hypothesis isect_memberFormation hypothesisEquality lambdaFormation independent_functionElimination dependent_pairFormation dependent_set_memberEquality natural_numberEquality sqequalRule independent_pairFormation setElimination rename lambdaEquality applyEquality functionEquality cumulativity universeEquality

Latex:
\mforall{}[P:(\mBbbB{}  List)  {}\mrightarrow{}  \mBbbP{}].  ((\mforall{}L:\mBbbB{}  List.  Dec(P[L]))  {}\mRightarrow{}  (\mforall{}n:\mBbbN{}.  Dec(\mexists{}L:\mBbbB{}  List.  ((||L||  =  n)  \mwedge{}  P[L]))))



Date html generated: 2016_05_14-PM-04_06_51
Last ObjectModification: 2015_12_26-PM-07_41_41

Theory : equipollence!!cardinality!


Home Index