Nuprl Lemma : bl-exists-first

[A:Type]. ∀P:A ⟶ 𝔹. ∀L:A List.  (↑(∃x∈L.P[x])_b ⇐⇒ ∃i:ℕ||L||. ((↑P[L[i]]) ∧ (∀j:ℕi. (¬↑P[L[j]]))))


Proof




Definitions occuring in Statement :  bl-exists: (∃x∈L.P[x])_b select: L[n] length: ||as|| list: List int_seg: {i..j-} assert: b bool: 𝔹 uall: [x:A]. B[x] so_apply: x[s] all: x:A. B[x] exists: x:A. B[x] iff: ⇐⇒ Q not: ¬A and: P ∧ Q function: x:A ⟶ B[x] natural_number: $n universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] member: t ∈ T so_lambda: λ2x.t[x] prop: so_apply: x[s] and: P ∧ Q int_seg: {i..j-} uimplies: supposing a guard: {T} lelt: i ≤ j < k decidable: Dec(P) or: P ∨ Q satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False implies:  Q not: ¬A top: Top less_than: a < b squash: T select: L[n] nil: [] it: so_lambda: λ2y.t[x; y] so_apply: x[s1;s2] iff: ⇐⇒ Q rev_implies:  Q subtype_rel: A ⊆B ge: i ≥  le: A ≤ B less_than': less_than'(a;b) nat_plus: + true: True uiff: uiff(P;Q) cons: [a b] cand: c∧ B subtract: m
Lemmas referenced :  list_induction iff_wf l_exists_wf l_member_wf assert_wf exists_wf int_seg_wf length_wf select_wf int_seg_properties decidable__le satisfiable-full-omega-tt intformand_wf intformnot_wf intformle_wf itermConstant_wf itermVar_wf int_formula_prop_and_lemma int_formula_prop_not_lemma int_formula_prop_le_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_wf decidable__lt intformless_wf int_formula_prop_less_lemma all_wf not_wf list_wf length_of_nil_lemma stuck-spread base_wf length_of_cons_lemma assert-bl-exists bl-exists_wf bool_wf l_exists_nil l_exists_wf_nil cons_wf non_neg_length itermAdd_wf int_term_value_add_lemma l_exists_cons decidable__assert false_wf add_nat_plus length_wf_nat less_than_wf nat_plus_wf nat_plus_properties add-is-int-iff intformeq_wf int_formula_prop_eq_lemma equal_wf lelt_wf add-member-int_seg2 subtract_wf itermSubtract_wf int_term_value_subtract_lemma select-cons-tl add-subtract-cancel decidable__equal_int assert_functionality_wrt_uiff squash_wf le_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation cut thin introduction extract_by_obid sqequalHypSubstitution isectElimination hypothesisEquality sqequalRule lambdaEquality cumulativity hypothesis setElimination rename applyEquality functionExtensionality because_Cache setEquality natural_numberEquality productEquality independent_isectElimination productElimination dependent_functionElimination unionElimination dependent_pairFormation int_eqEquality intEquality isect_memberEquality voidElimination voidEquality independent_pairFormation computeAll imageElimination independent_functionElimination baseClosed addLevel impliesFunctionality functionEquality universeEquality addEquality dependent_set_memberEquality imageMemberEquality equalityTransitivity equalitySymmetry applyLambdaEquality pointwiseFunctionality promote_hyp baseApply closedConclusion inlFormation inrFormation

Latex:
\mforall{}[A:Type]
    \mforall{}P:A  {}\mrightarrow{}  \mBbbB{}.  \mforall{}L:A  List.    (\muparrow{}(\mexists{}x\mmember{}L.P[x])\_b  \mLeftarrow{}{}\mRightarrow{}  \mexists{}i:\mBbbN{}||L||.  ((\muparrow{}P[L[i]])  \mwedge{}  (\mforall{}j:\mBbbN{}i.  (\mneg{}\muparrow{}P[L[j]]))))



Date html generated: 2017_04_17-AM-08_04_08
Last ObjectModification: 2017_02_27-PM-04_34_38

Theory : list_1


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