Nuprl Lemma : can-find-first2

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


Proof




Definitions occuring in Statement :  first-member: first-member(T;x;L;P) l_all: (∀x∈L.P[x]) l_member: (x ∈ l) list: List assert: b bool: 𝔹 uall: [x:A]. B[x] all: x:A. B[x] sq_exists: x:A [B[x]] not: ¬A or: P ∨ Q set: {x:A| B[x]}  apply: a function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] member: t ∈ T prop: or: P ∨ Q so_lambda: λ2x.t[x] so_apply: x[s] sq_exists: x:A [B[x]] first-member: first-member(T;x;L;P) exists: x:A. B[x] and: P ∧ Q cand: c∧ B subtype_rel: A ⊆B uimplies: supposing a guard: {T} implies:  Q int_seg: {i..j-} lelt: i ≤ j < k decidable: Dec(P) satisfiable_int_formula: satisfiable_int_formula(fmla) false: False not: ¬A top: Top less_than: a < b squash: T l_member: (x ∈ l) le: A ≤ B less_than': less_than'(a;b) nat: ge: i ≥ 
Lemmas referenced :  can-find-first1-ext l_member_wf list-subtype bool_wf list_wf l_all_wf2 not_wf assert_wf equal_functionality_wrt_subtype_rel2 equal_wf select_wf int_seg_properties length_wf 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 int_seg_wf exists_wf int_seg_subtype_nat false_wf less_than_wf nat_properties sq_exists_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation cut introduction extract_by_obid sqequalHypSubstitution isectElimination thin setEquality cumulativity hypothesisEquality hypothesis dependent_functionElimination because_Cache equalityTransitivity equalitySymmetry rename functionEquality universeEquality unionElimination inlEquality sqequalRule lambdaEquality applyEquality functionExtensionality setElimination dependent_set_memberEquality inrEquality productElimination dependent_pairFormation independent_isectElimination independent_functionElimination independent_pairFormation productEquality natural_numberEquality int_eqEquality intEquality isect_memberEquality voidElimination voidEquality computeAll imageElimination

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



Date html generated: 2018_05_21-PM-06_34_16
Last ObjectModification: 2017_07_26-PM-04_52_29

Theory : general


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