Nuprl Lemma : select_tl

[A:Type]. ∀[as:A List]. ∀[n:ℕ||as|| 1].  (tl(as)[n] as[n 1] ∈ A)


Proof




Definitions occuring in Statement :  select: L[n] length: ||as|| tl: tl(l) list: List int_seg: {i..j-} uall: [x:A]. B[x] subtract: m add: m natural_number: $n universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T so_lambda: λ2x.t[x] int_seg: {i..j-} uimplies: supposing a sq_stable: SqStable(P) implies:  Q lelt: i ≤ j < k and: P ∧ Q squash: T prop: all: x:A. B[x] ge: i ≥  decidable: Dec(P) or: P ∨ Q iff: ⇐⇒ Q not: ¬A rev_implies:  Q false: False uiff: uiff(P;Q) subtract: m subtype_rel: A ⊆B top: Top le: A ≤ B less_than': less_than'(a;b) true: True guard: {T} so_apply: x[s] select: L[n] nil: [] it: so_lambda: λ2y.t[x; y] so_apply: x[s1;s2]
Lemmas referenced :  add-subtract-cancel select-cons-tl reduce_tl_cons_lemma length_of_cons_lemma le-add-cancel2 base_wf stuck-spread reduce_tl_nil_lemma length_of_nil_lemma list_wf not-lt-2 decidable__lt add-zero not-le-2 iff_weakening_equal le-add-cancel add_functionality_wrt_le zero-add add-commutes minus-one-mul-top add-swap minus-one-mul minus-add add-associates condition-implies-le less-iff-le not-ge-2 false_wf decidable__le length_tl true_wf squash_wf less_than_wf sq_stable__le tl_wf select_wf equal_wf length_wf subtract_wf int_seg_wf uall_wf list_induction
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut thin lemma_by_obid sqequalHypSubstitution isectElimination hypothesisEquality sqequalRule lambdaEquality natural_numberEquality cumulativity hypothesis because_Cache setElimination rename independent_isectElimination independent_functionElimination productElimination imageMemberEquality baseClosed imageElimination applyEquality equalityTransitivity equalitySymmetry intEquality dependent_functionElimination unionElimination independent_pairFormation lambdaFormation voidElimination addEquality minusEquality isect_memberEquality voidEquality universeEquality axiomEquality

Latex:
\mforall{}[A:Type].  \mforall{}[as:A  List].  \mforall{}[n:\mBbbN{}||as||  -  1].    (tl(as)[n]  =  as[n  +  1])



Date html generated: 2016_05_14-AM-06_36_37
Last ObjectModification: 2016_01_06-PM-08_33_28

Theory : list_0


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