Nuprl Lemma : select_l_index

[T:Type]. ∀[dT:EqDecider(T)]. ∀[L:T List]. ∀[x:T].  L[index(L;x)] x ∈ supposing (x ∈ L)


Proof




Definitions occuring in Statement :  l_index: index(L;x) l_member: (x ∈ l) select: L[n] list: List deq: EqDecider(T) uimplies: supposing a uall: [x:A]. B[x] universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a prop: l_index: index(L;x) deq: EqDecider(T) int_seg: {i..j-} guard: {T} lelt: i ≤ j < k and: P ∧ Q all: x:A. B[x] 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 uiff: uiff(P;Q) eqof: eqof(d) so_lambda: λ2x.t[x] so_apply: x[s] l_member: (x ∈ l) nat: le: A ≤ B cand: c∧ B ge: i ≥  subtype_rel: A ⊆B true: True iff: ⇐⇒ Q rev_implies:  Q
Lemmas referenced :  l_member_wf list_wf deq_wf mu-bound-property length_wf_nat 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 int_seg_wf safe-assert-deq assert_wf eqof_wf exists_wf equal_wf lelt_wf nat_properties deq_property l_index_wf non_neg_length squash_wf true_wf iff_weakening_equal
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut hypothesis extract_by_obid sqequalHypSubstitution isectElimination thin cumulativity hypothesisEquality sqequalRule isect_memberEquality axiomEquality because_Cache equalityTransitivity equalitySymmetry universeEquality lambdaEquality applyEquality setElimination rename independent_isectElimination natural_numberEquality productElimination dependent_functionElimination unionElimination dependent_pairFormation int_eqEquality intEquality voidElimination voidEquality independent_pairFormation computeAll imageElimination addLevel existsFunctionality levelHypothesis existsLevelFunctionality dependent_set_memberEquality applyLambdaEquality independent_functionElimination imageMemberEquality baseClosed

Latex:
\mforall{}[T:Type].  \mforall{}[dT:EqDecider(T)].  \mforall{}[L:T  List].  \mforall{}[x:T].    L[index(L;x)]  =  x  supposing  (x  \mmember{}  L)



Date html generated: 2017_04_17-AM-09_15_59
Last ObjectModification: 2017_02_27-PM-05_21_24

Theory : decidable!equality


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