Nuprl Lemma : strict-majority-or-max-property
∀t:ℕ. ∀L:ℤ List.
  ((∀v:ℤ
      (strict-majority-or-max(L) = v ∈ ℤ) supposing 
         (((t + 1) ≤ ||filter(λx.(x =z v);L)||) and 
         (||L|| = ((2 * t) + 1) ∈ ℤ)))
  ∧ (strict-majority-or-max(L) ∈ L) supposing ||L|| ≥ 1 )
Proof
Definitions occuring in Statement : 
strict-majority-or-max: strict-majority-or-max(L)
, 
l_member: (x ∈ l)
, 
length: ||as||
, 
filter: filter(P;l)
, 
list: T List
, 
nat: ℕ
, 
eq_int: (i =z j)
, 
uimplies: b supposing a
, 
ge: i ≥ j 
, 
le: A ≤ B
, 
all: ∀x:A. B[x]
, 
and: P ∧ Q
, 
lambda: λx.A[x]
, 
multiply: n * m
, 
add: n + m
, 
natural_number: $n
, 
int: ℤ
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
strict-majority-or-max: strict-majority-or-max(L)
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
nat: ℕ
, 
subtype_rel: A ⊆r B
, 
ge: i ≥ j 
, 
le: A ≤ B
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
false: False
, 
uiff: uiff(P;Q)
, 
int-deq: IntDeq
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
top: Top
, 
sq_type: SQType(T)
, 
guard: {T}
, 
l_all: (∀x∈L.P[x])
, 
int_seg: {i..j-}
, 
lelt: i ≤ j < k
, 
less_than: a < b
, 
squash: ↓T
, 
rev_uimplies: rev_uimplies(P;Q)
, 
nequal: a ≠ b ∈ T 
, 
l_member: (x ∈ l)
, 
less_than': less_than'(a;b)
, 
strict-majority: strict-majority(eq;L)
, 
let: let, 
ifthenelse: if b then t else f fi 
, 
null: null(as)
, 
filter: filter(P;l)
, 
reduce: reduce(f;k;as)
, 
list_ind: list_ind, 
count-repeats: count-repeats(L,eq)
, 
list_accum: list_accum, 
nil: []
, 
it: ⋅
, 
btrue: tt
, 
true: True
, 
cons: [a / b]
, 
bfalse: ff
Lemmas referenced : 
le_wf, 
length_wf, 
filter_wf5, 
eq_int_wf, 
l_member_wf, 
equal-wf-base-T, 
list_subtype_base, 
int_subtype_base, 
less_than'_wf, 
ge_wf, 
list_wf, 
nat_wf, 
strict-majority-property, 
int-deq_wf, 
nat_properties, 
decidable__lt, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformnot_wf, 
intformless_wf, 
itermVar_wf, 
itermMultiply_wf, 
itermConstant_wf, 
intformle_wf, 
itermAdd_wf, 
intformeq_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_less_lemma, 
int_term_value_var_lemma, 
int_term_value_mul_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_le_lemma, 
int_term_value_add_lemma, 
int_formula_prop_eq_lemma, 
int_formula_prop_wf, 
subtype_base_sq, 
unit_wf2, 
union_subtype_base, 
unit_subtype_base, 
strict-majority_wf, 
equal_wf, 
decidable__l_member, 
decidable__equal_int, 
filter_is_nil, 
assert_wf, 
select_wf, 
int_seg_properties, 
decidable__le, 
int_seg_wf, 
length_of_nil_lemma, 
neg_assert_of_eq_int, 
int_seg_subtype_nat, 
false_wf, 
less_than_wf, 
equal-wf-T-base, 
list-cases, 
filter_nil_lemma, 
null_nil_lemma, 
product_subtype_list, 
length_of_cons_lemma, 
filter_cons_lemma, 
null_cons_lemma, 
imax-list-member, 
cons_wf, 
add-is-int-iff
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
isect_memberFormation, 
introduction, 
hypothesis, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
addEquality, 
setElimination, 
rename, 
hypothesisEquality, 
natural_numberEquality, 
intEquality, 
lambdaEquality, 
setEquality, 
sqequalRule, 
isect_memberEquality, 
axiomEquality, 
because_Cache, 
equalityTransitivity, 
equalitySymmetry, 
baseApply, 
closedConclusion, 
baseClosed, 
applyEquality, 
independent_isectElimination, 
multiplyEquality, 
independent_pairFormation, 
productElimination, 
independent_pairEquality, 
dependent_functionElimination, 
voidElimination, 
unionElimination, 
dependent_pairFormation, 
int_eqEquality, 
voidEquality, 
computeAll, 
instantiate, 
cumulativity, 
unionEquality, 
independent_functionElimination, 
imageElimination, 
productEquality, 
promote_hyp, 
hypothesis_subsumption, 
pointwiseFunctionality
Latex:
\mforall{}t:\mBbbN{}.  \mforall{}L:\mBbbZ{}  List.
    ((\mforall{}v:\mBbbZ{}
            (strict-majority-or-max(L)  =  v)  supposing 
                  (((t  +  1)  \mleq{}  ||filter(\mlambda{}x.(x  =\msubz{}  v);L)||)  and 
                  (||L||  =  ((2  *  t)  +  1))))
    \mwedge{}  (strict-majority-or-max(L)  \mmember{}  L)  supposing  ||L||  \mgeq{}  1  )
Date html generated:
2017_04_17-AM-09_09_44
Last ObjectModification:
2017_02_27-PM-05_17_59
Theory : decidable!equality
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