Nuprl Lemma : three-cs-int-safety
∀A:Id List. ∀t:ℕ+.
  (∀v:ℤ. ∀s:ts-reachable(three-consensus-ts(ℤ;A;t;λL.strict-majority-or-max(L))).
     (three-cs-decided(ℤ;A;t;λL.strict-majority-or-max(L);s;v)
     
⇒ ((∃a∈A. (||s a|| ≥ 1 ) ∧ (hd(s a) = Init[v] ∈ consensus-rcv(ℤ;A)))
        ∧ (∀w:ℤ. ∀s':ts-reachable(three-consensus-ts(ℤ;A;t;λL.strict-majority-or-max(L))).
             ((s (ts-rel(three-consensus-ts(ℤ;A;t;λL.strict-majority-or-max(L)))^*) s')
             
⇒ three-cs-decided(ℤ;A;t;λL.strict-majority-or-max(L);s';w)
             
⇒ (v = w ∈ ℤ)))))) supposing 
     ((||A|| = ((3 * t) + 1) ∈ ℤ) and 
     no_repeats(Id;A))
Proof
Definitions occuring in Statement : 
three-cs-decided: three-cs-decided(V;A;t;f;s;v)
, 
three-consensus-ts: three-consensus-ts(V;A;t;f)
, 
cs-initial-rcv: Init[v]
, 
consensus-rcv: consensus-rcv(V;A)
, 
Id: Id
, 
strict-majority-or-max: strict-majority-or-max(L)
, 
l_exists: (∃x∈L. P[x])
, 
no_repeats: no_repeats(T;l)
, 
hd: hd(l)
, 
length: ||as||
, 
list: T List
, 
rel_star: R^*
, 
nat_plus: ℕ+
, 
uimplies: b supposing a
, 
infix_ap: x f y
, 
ge: i ≥ j 
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
apply: f a
, 
lambda: λx.A[x]
, 
multiply: n * m
, 
add: n + m
, 
natural_number: $n
, 
int: ℤ
, 
equal: s = t ∈ T
, 
ts-reachable: ts-reachable(ts)
, 
ts-rel: ts-rel(ts)
, 
ts-type: ts-type(ts)
Lemmas : 
three-cs-safety, 
int-deq_wf, 
no_repeats_witness, 
Id_wf, 
strict-majority-or-max-property, 
nat_plus_subtype_nat, 
strict-majority-or-max_wf, 
list_wf, 
le_wf, 
length_wf, 
filter_wf5, 
l_member_wf, 
eqof_wf, 
equal-wf-base-T, 
list_subtype_base, 
int_subtype_base, 
less_than_wf, 
ge_wf, 
equal_wf, 
no_repeats_wf, 
nat_plus_wf
\mforall{}A:Id  List.  \mforall{}t:\mBbbN{}\msupplus{}.
    (\mforall{}v:\mBbbZ{}.  \mforall{}s:ts-reachable(three-consensus-ts(\mBbbZ{};A;t;\mlambda{}L.strict-majority-or-max(L))).
          (three-cs-decided(\mBbbZ{};A;t;\mlambda{}L.strict-majority-or-max(L);s;v)
          {}\mRightarrow{}  ((\mexists{}a\mmember{}A.  (||s  a||  \mgeq{}  1  )  \mwedge{}  (hd(s  a)  =  Init[v]))
                \mwedge{}  (\mforall{}w:\mBbbZ{}.  \mforall{}s':ts-reachable(three-consensus-ts(\mBbbZ{};A;t;\mlambda{}L.strict-majority-or-max(L))).
                          ((s 
                              (ts-rel(three-consensus-ts(\mBbbZ{};A;t;\mlambda{}L.strict-majority-or-max(L)))\^{}*) 
                              s')
                          {}\mRightarrow{}  three-cs-decided(\mBbbZ{};A;t;\mlambda{}L.strict-majority-or-max(L);s';w)
                          {}\mRightarrow{}  (v  =  w))))))  supposing 
          ((||A||  =  ((3  *  t)  +  1))  and 
          no\_repeats(Id;A))
Date html generated:
2015_07_17-AM-11_54_25
Last ObjectModification:
2015_01_28-AM-00_43_07
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