Nuprl Lemma : lastn-0

[L:Top List]. ∀[n:ℤ].  lastn(n;L) [] supposing n ≤ 0


Proof




Definitions occuring in Statement :  lastn: lastn(n;L) nil: [] list: List uimplies: supposing a uall: [x:A]. B[x] top: Top le: A ≤ B natural_number: $n int: sqequal: t
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a prop: subtype_rel: A ⊆B satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False implies:  Q not: ¬A all: x:A. B[x] top: Top and: P ∧ Q bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) ifthenelse: if then else fi  bfalse: ff guard: {T} or: P ∨ Q cons: [a b] ge: i ≥  le: A ≤ B
Lemmas referenced :  lastn-cases le_wf list_wf top_wf le_int_wf length_wf bool_wf equal-wf-T-base assert_wf lt_int_wf less_than_wf bnot_wf equal-wf-base int_subtype_base satisfiable-full-omega-tt intformand_wf intformless_wf itermConstant_wf itermVar_wf intformle_wf int_formula_prop_and_lemma int_formula_prop_less_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_le_lemma int_formula_prop_wf uiff_transitivity eqtt_to_assert assert_of_le_int eqff_to_assert assert_functionality_wrt_uiff bnot_of_le_int assert_of_lt_int equal_wf list-cases length_of_nil_lemma product_subtype_list length_of_cons_lemma non_neg_length itermAdd_wf int_term_value_add_lemma
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut sqequalRule extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis sqequalAxiom natural_numberEquality isect_memberEquality because_Cache equalityTransitivity equalitySymmetry intEquality baseClosed baseApply closedConclusion applyEquality independent_isectElimination dependent_pairFormation lambdaEquality int_eqEquality dependent_functionElimination voidElimination voidEquality independent_pairFormation computeAll lambdaFormation unionElimination equalityElimination independent_functionElimination productElimination promote_hyp hypothesis_subsumption

Latex:
\mforall{}[L:Top  List].  \mforall{}[n:\mBbbZ{}].    lastn(n;L)  \msim{}  []  supposing  n  \mleq{}  0



Date html generated: 2018_05_21-PM-06_31_50
Last ObjectModification: 2017_07_26-PM-04_51_19

Theory : general


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