Nuprl Lemma : firstn_nth_tl_decomp

[T:Type]. ∀[L:T List]. ∀[i:ℕ||L||].  (L firstn(i;L) [L[i]] nth_tl(1 i;L))


Proof




Definitions occuring in Statement :  firstn: firstn(n;as) select: L[n] length: ||as|| nth_tl: nth_tl(n;as) append: as bs cons: [a b] nil: [] list: List int_seg: {i..j-} uall: [x:A]. B[x] add: m natural_number: $n universe: Type sqequal: t
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T append: as bs all: x:A. B[x] so_lambda: so_lambda(x,y,z.t[x; y; z]) top: Top so_apply: x[s1;s2;s3] subtype_rel: A ⊆B uimplies: supposing a le: A ≤ B and: P ∧ Q less_than': less_than'(a;b) false: False not: ¬A implies:  Q prop: int_seg: {i..j-} lelt: i ≤ j < k decidable: Dec(P) or: P ∨ Q less_than: a < b squash: T satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x]
Lemmas referenced :  list_wf int_seg_wf lelt_wf int_formula_prop_wf int_term_value_constant_lemma int_term_value_add_lemma int_term_value_var_lemma int_formula_prop_less_lemma int_formula_prop_not_lemma int_formula_prop_and_lemma itermConstant_wf itermAdd_wf itermVar_wf intformless_wf intformnot_wf intformand_wf satisfiable-full-omega-tt decidable__lt top_wf subtype_rel_list append_firstn_lastn_sq int_seg_properties false_wf length_wf int_seg_subtype_nat nth_tl_decomp list_ind_nil_lemma list_ind_cons_lemma
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut sqequalRule lemma_by_obid sqequalHypSubstitution dependent_functionElimination thin isect_memberEquality voidElimination voidEquality hypothesis isectElimination hypothesisEquality applyEquality natural_numberEquality independent_isectElimination independent_pairFormation lambdaFormation setElimination rename productElimination lambdaEquality because_Cache dependent_set_memberEquality addEquality unionElimination imageElimination dependent_pairFormation int_eqEquality intEquality computeAll cumulativity sqequalAxiom universeEquality

Latex:
\mforall{}[T:Type].  \mforall{}[L:T  List].  \mforall{}[i:\mBbbN{}||L||].    (L  \msim{}  firstn(i;L)  @  [L[i]]  @  nth\_tl(1  +  i;L))



Date html generated: 2016_05_14-PM-02_07_57
Last ObjectModification: 2016_01_15-AM-08_03_15

Theory : list_1


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