Nuprl Lemma : decidable-exists-finite

[T:Type]. (finite(T)  (∀[P:T ⟶ ℙ]. ((∀t:T. Dec(P[t]))  Dec(∃t:T. P[t]))))


Proof




Definitions occuring in Statement :  finite: finite(T) 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 function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T implies:  Q prop: finite: finite(T) exists: x:A. B[x] finite-type: finite-type(T) nat: so_lambda: λ2x.t[x] so_apply: x[s] guard: {T} equipollent: B biject: Bij(A;B;f) and: P ∧ Q
Lemmas referenced :  decidable-exists-finite-type finite_wf exists_wf int_seg_wf surject_wf equipollent_inversion
Rules used in proof :  cut introduction extract_by_obid sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation hypothesis sqequalHypSubstitution isectElimination thin hypothesisEquality lambdaFormation independent_functionElimination cumulativity universeEquality productElimination dependent_pairFormation functionEquality natural_numberEquality setElimination rename sqequalRule lambdaEquality because_Cache functionExtensionality applyEquality

Latex:
\mforall{}[T:Type].  (finite(T)  {}\mRightarrow{}  (\mforall{}[P:T  {}\mrightarrow{}  \mBbbP{}].  ((\mforall{}t:T.  Dec(P[t]))  {}\mRightarrow{}  Dec(\mexists{}t:T.  P[t]))))



Date html generated: 2016_10_21-AM-11_00_13
Last ObjectModification: 2016_08_08-AM-11_27_08

Theory : equipollence!!cardinality!


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