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: T List
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
top: Top
, 
le: A ≤ B
, 
natural_number: $n
, 
int: ℤ
, 
sqequal: s ~ t
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
false: False
, 
implies: P 
⇒ 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 b then t else f fi 
, 
bfalse: ff
, 
guard: {T}
, 
or: P ∨ Q
, 
cons: [a / b]
, 
ge: i ≥ j 
, 
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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