Nuprl Lemma : decidable__wellfound-bounded-exists
∀[T:Type]. ∀[R:T ⟶ T ⟶ ℙ]. ∀[P:T ⟶ ℙ].
  ((∀x,y:T.  Dec(R x y))
  
⇒ (∀x:T. Dec(P[x]))
  
⇒ (∀y:T. ∃L:T List. ∀x:T. ((R x y) 
⇒ (x ∈ L)))
  
⇒ WellFnd{i}(T;x,y.R x y)
  
⇒ (∀y:T. Dec(∃x:T. ((R+ x y) ∧ P[x]))))
Proof
Definitions occuring in Statement : 
rel_plus: R+
, 
l_member: (x ∈ l)
, 
list: T List
, 
wellfounded: WellFnd{i}(A;x,y.R[x; y])
, 
decidable: Dec(P)
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
implies: P 
⇒ Q
, 
wellfounded: WellFnd{i}(A;x,y.R[x; y])
, 
so_lambda: λ2x.t[x]
, 
member: t ∈ T
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
guard: {T}
, 
so_lambda: λ2x y.t[x; y]
, 
so_apply: x[s1;s2]
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
l_exists: (∃x∈L. P[x])
, 
int_seg: {i..j-}
, 
uimplies: b supposing a
, 
lelt: i ≤ j < k
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
false: False
, 
not: ¬A
, 
top: Top
, 
less_than: a < b
, 
squash: ↓T
, 
infix_ap: x f y
, 
trans: Trans(T;x,y.E[x; y])
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
l_exists_iff, 
rel_plus_implies, 
rel_plus_trans, 
rel-rel-plus, 
int_formula_prop_less_lemma, 
intformless_wf, 
decidable__lt, 
int_formula_prop_wf, 
int_term_value_var_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_le_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_and_lemma, 
itermVar_wf, 
itermConstant_wf, 
intformle_wf, 
intformnot_wf, 
intformand_wf, 
satisfiable-full-omega-tt, 
decidable__le, 
length_wf, 
int_seg_properties, 
select_wf, 
not_wf, 
decidable__cand, 
decidable__l_exists_better-extract, 
decidable__and, 
decidable__l_exists, 
l_member_wf, 
list_wf, 
wellfounded_wf, 
all_wf, 
rel_plus_wf, 
and_wf, 
exists_wf, 
decidable_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
sqequalHypSubstitution, 
cut, 
hypothesis, 
isectElimination, 
thin, 
sqequalRule, 
lambdaEquality, 
lemma_by_obid, 
hypothesisEquality, 
applyEquality, 
because_Cache, 
independent_functionElimination, 
rename, 
dependent_functionElimination, 
productElimination, 
functionEquality, 
cumulativity, 
universeEquality, 
isect_memberEquality, 
unionElimination, 
inlFormation, 
dependent_pairFormation, 
setElimination, 
independent_isectElimination, 
natural_numberEquality, 
int_eqEquality, 
intEquality, 
voidElimination, 
voidEquality, 
independent_pairFormation, 
computeAll, 
imageElimination, 
inrFormation, 
productEquality, 
setEquality
Latex:
\mforall{}[T:Type].  \mforall{}[R:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbP{}].
    ((\mforall{}x,y:T.    Dec(R  x  y))
    {}\mRightarrow{}  (\mforall{}x:T.  Dec(P[x]))
    {}\mRightarrow{}  (\mforall{}y:T.  \mexists{}L:T  List.  \mforall{}x:T.  ((R  x  y)  {}\mRightarrow{}  (x  \mmember{}  L)))
    {}\mRightarrow{}  WellFnd\{i\}(T;x,y.R  x  y)
    {}\mRightarrow{}  (\mforall{}y:T.  Dec(\mexists{}x:T.  ((R\msupplus{}  x  y)  \mwedge{}  P[x]))))
Date html generated:
2016_05_15-PM-04_52_03
Last ObjectModification:
2016_01_16-AM-11_29_16
Theory : general
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