Nuprl Lemma : find-first_wf

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


Proof




Definitions occuring in Statement :  find-first: find-first(P;L) 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] sq_exists: x:A [B[x]] not: ¬A or: P ∨ Q member: t ∈ T set: {x:A| B[x]}  apply: a function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T find-first: find-first(P;L) prop: can-find-first-ext all: x:A. B[x] implies:  Q first-member: first-member(T;x;L;P) subtype_rel: A ⊆B or: P ∨ Q so_lambda: λ2x.t[x] and: P ∧ Q int_seg: {i..j-} uimplies: supposing a guard: {T} lelt: i ≤ j < k decidable: Dec(P) not: ¬A satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False top: Top less_than: a < b squash: T l_member: (x ∈ l) le: A ≤ B less_than': less_than'(a;b) cand: c∧ B nat: ge: i ≥  so_apply: x[s] sq_exists: x:A [B[x]]
Lemmas referenced :  istype-universe l_member_wf bool_wf list_wf can-find-first-ext sq_exists_wf exists_wf int_seg_wf length_wf equal_wf select_wf int_seg_properties decidable__le full-omega-unsat intformand_wf intformnot_wf intformle_wf itermConstant_wf itermVar_wf istype-int int_formula_prop_and_lemma istype-void 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 assert_wf int_seg_subtype_nat istype-false less_than_wf nat_properties not_wf select_member le_wf l_all_wf2
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt cut sqequalHypSubstitution hypothesis functionIsType setIsType introduction extract_by_obid isectElimination thin hypothesisEquality universeIsType universeEquality sqequalRule instantiate inhabitedIsType lambdaFormation_alt equalityIsType1 equalityTransitivity equalitySymmetry dependent_functionElimination independent_functionElimination applyEquality lambdaEquality_alt isectIsType unionIsType natural_numberEquality productEquality because_Cache setElimination rename independent_isectElimination productElimination unionElimination approximateComputation dependent_pairFormation_alt int_eqEquality isect_memberEquality_alt voidElimination independent_pairFormation imageElimination productIsType dependent_set_memberEquality_alt functionEquality

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



Date html generated: 2019_10_15-AM-11_08_07
Last ObjectModification: 2018_10_09-PM-03_14_28

Theory : general


Home Index