Nuprl Lemma : l-first_wf

[T:Type]. ∀[f:T ⟶ 𝔹]. ∀[L:T List].  (l-first(x.f[x];L) ∈ (∃x:{T| ((x ∈ L) ∧ (↑f[x]))}) ∨ (∀x∈L.¬↑f[x]))


Proof




Definitions occuring in Statement :  l-first: l-first(x.f[x];L) l_all: (∀x∈L.P[x]) l_member: (x ∈ l) list: List assert: b bool: 𝔹 uall: [x:A]. B[x] so_apply: x[s] sq_exists: x:{A| B[x]} not: ¬A or: P ∨ Q and: P ∧ Q member: t ∈ T function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  l-first: l-first(x.f[x];L) uall: [x:A]. B[x] member: t ∈ T all: x:A. B[x] nat: implies:  Q false: False ge: i ≥  uimplies: supposing a satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] not: ¬A top: Top and: P ∧ Q prop: subtype_rel: A ⊆B guard: {T} or: P ∨ Q so_lambda: so_lambda(x,y,z.t[x; y; z]) so_apply: x[s1;s2;s3] l_all: (∀x∈L.P[x]) select: L[n] nil: [] it: so_lambda: λ2y.t[x; y] so_apply: x[s1;s2] int_seg: {i..j-} lelt: i ≤ j < k so_lambda: λ2x.t[x] so_apply: x[s] sq_exists: x:{A| B[x]} cons: [a b] colength: colength(L) decidable: Dec(P) sq_type: SQType(T) less_than: a < b squash: T less_than': less_than'(a;b) exposed-it: exposed-it bool: 𝔹 unit: Unit btrue: tt uiff: uiff(P;Q) ifthenelse: if then else fi  cand: c∧ B iff: ⇐⇒ Q rev_implies:  Q bfalse: ff bnot: ¬bb assert: b le: A ≤ B
Lemmas referenced :  nat_properties satisfiable-full-omega-tt intformand_wf intformle_wf itermConstant_wf itermVar_wf intformless_wf int_formula_prop_and_lemma int_formula_prop_le_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_less_lemma int_formula_prop_wf ge_wf less_than_wf equal-wf-T-base nat_wf colength_wf_list less_than_transitivity1 less_than_irreflexivity list-cases list_ind_nil_lemma stuck-spread base_wf length_of_nil_lemma int_seg_properties int_seg_wf length_wf nil_wf sq_exists_wf l_member_wf assert_wf product_subtype_list spread_cons_lemma intformeq_wf itermAdd_wf int_formula_prop_eq_lemma int_term_value_add_lemma decidable__le intformnot_wf int_formula_prop_not_lemma le_wf equal_wf subtract_wf itermSubtract_wf int_term_value_subtract_lemma subtype_base_sq set_subtype_base int_subtype_base decidable__equal_int list_ind_cons_lemma bool_wf eqtt_to_assert cons_member cons_wf l_all_wf not_wf eqff_to_assert bool_cases_sqequal bool_subtype_base assert-bnot or_wf list_wf subtype_rel_sets length_of_cons_lemma select_wf non_neg_length decidable__lt select-cons le_int_wf bnot_wf bool_cases assert_of_le_int iff_transitivity iff_weakening_uiff assert_of_bnot add-is-int-iff false_wf lelt_wf
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep isect_memberFormation introduction cut thin lambdaFormation extract_by_obid sqequalHypSubstitution isectElimination hypothesisEquality hypothesis setElimination rename intWeakElimination natural_numberEquality independent_isectElimination dependent_pairFormation lambdaEquality int_eqEquality intEquality dependent_functionElimination isect_memberEquality voidElimination voidEquality independent_pairFormation computeAll independent_functionElimination axiomEquality equalityTransitivity equalitySymmetry cumulativity applyEquality because_Cache unionElimination inrEquality baseClosed productElimination productEquality functionExtensionality promote_hyp hypothesis_subsumption applyLambdaEquality dependent_set_memberEquality addEquality instantiate imageElimination equalityElimination inlEquality inlFormation setEquality functionEquality universeEquality inrFormation impliesFunctionality pointwiseFunctionality baseApply closedConclusion

Latex:
\mforall{}[T:Type].  \mforall{}[f:T  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[L:T  List].
    (l-first(x.f[x];L)  \mmember{}  (\mexists{}x:\{T|  ((x  \mmember{}  L)  \mwedge{}  (\muparrow{}f[x]))\})  \mvee{}  (\mforall{}x\mmember{}L.\mneg{}\muparrow{}f[x]))



Date html generated: 2017_04_17-AM-07_24_49
Last ObjectModification: 2017_02_27-PM-04_03_56

Theory : list_1


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