Nuprl Lemma : decidable__l_exists-proof

[A:Type]. ∀[F:A ⟶ ℙ].  ∀L:A List. ((∀k:A. Dec(F[k]))  Dec((∃k∈L. F[k])))


Proof




Definitions occuring in Statement :  l_exists: (∃x∈L. P[x]) list: List decidable: Dec(P) uall: [x:A]. B[x] prop: so_apply: x[s] all: x:A. B[x] implies:  Q function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  l_exists: (∃x∈L. P[x]) uall: [x:A]. B[x] all: x:A. B[x] implies:  Q member: t ∈ T so_lambda: λ2x.t[x] so_apply: x[s] int_seg: {i..j-} uimplies: supposing a guard: {T} lelt: i ≤ j < k and: P ∧ Q decidable: Dec(P) or: P ∨ Q satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False not: ¬A top: Top prop: less_than: a < b squash: T
Lemmas referenced :  list_wf decidable_wf all_wf int_seg_wf int_formula_prop_less_lemma intformless_wf decidable__lt int_formula_prop_wf int_term_value_var_lemma int_term_value_constant_lemma int_formula_prop_le_lemma int_formula_prop_not_lemma int_formula_prop_and_lemma itermVar_wf itermConstant_wf intformle_wf intformnot_wf intformand_wf satisfiable-full-omega-tt decidable__le int_seg_properties select_wf length_wf decidable__exists_int_seg
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep isect_memberFormation lambdaFormation cut thin instantiate lemma_by_obid sqequalHypSubstitution dependent_functionElimination natural_numberEquality isectElimination hypothesisEquality hypothesis lambdaEquality applyEquality cumulativity setElimination rename independent_isectElimination because_Cache productElimination unionElimination dependent_pairFormation int_eqEquality intEquality isect_memberEquality voidElimination voidEquality independent_pairFormation computeAll imageElimination independent_functionElimination introduction functionEquality universeEquality

Latex:
\mforall{}[A:Type].  \mforall{}[F:A  {}\mrightarrow{}  \mBbbP{}].    \mforall{}L:A  List.  ((\mforall{}k:A.  Dec(F[k]))  {}\mRightarrow{}  Dec((\mexists{}k\mmember{}L.  F[k])))



Date html generated: 2016_05_14-AM-07_47_52
Last ObjectModification: 2016_01_15-AM-08_33_00

Theory : list_1


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