Nuprl Lemma : power-set-lift-well-founded-implies
∀[T:Type]. ∀[R:T ⟶ T ⟶ ℙ].
  ((∀x:T. (R x x))
  
⇒ (∀f:ℕ ⟶ P(T). (↓∃n:ℕ. ((power-set-lift(T;R) (f (n + 1)) (f n)) 
⇒ (power-set-lift(T;R) (f n) (f (n + 1))))))
  
⇒ AFx,y:T.R[x;y])
Proof
Definitions occuring in Statement : 
power-set-lift: power-set-lift(T;R)
, 
power-set: P(T)
, 
almost-full: AFx,y:T.R[x; y]
, 
nat: ℕ
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s1;s2]
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
squash: ↓T
, 
implies: P 
⇒ Q
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
add: n + m
, 
natural_number: $n
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
implies: P 
⇒ Q
, 
almost-full: AFx,y:T.R[x; y]
, 
all: ∀x:A. B[x]
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
so_lambda: λ2x.t[x]
, 
nat: ℕ
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
not: ¬A
, 
rev_implies: P 
⇐ Q
, 
false: False
, 
uiff: uiff(P;Q)
, 
uimplies: b supposing a
, 
sq_stable: SqStable(P)
, 
squash: ↓T
, 
subtract: n - m
, 
top: Top
, 
le: A ≤ B
, 
less_than': less_than'(a;b)
, 
true: True
, 
so_apply: x[s]
, 
exists: ∃x:A. B[x]
, 
power-set: P(T)
, 
power-set-lift: power-set-lift(T;R)
, 
set-member: (x ∈ s)
, 
cand: A c∧ B
, 
guard: {T}
, 
int_upper: {i...}
, 
so_apply: x[s1;s2]
Lemmas referenced : 
iff_weakening_equal, 
less_than_wf, 
not-lt-2, 
decidable__lt, 
int_subtype_base, 
add-is-int-iff, 
le_reflexive, 
and_wf, 
equal_wf, 
le-add-cancel2, 
zero-mul, 
add-mul-special, 
int_upper_subtype_int_upper, 
int_upper_subtype_nat, 
subtype_rel_dep_function, 
int_upper_wf, 
le_wf, 
le-add-cancel, 
add-zero, 
add_functionality_wrt_le, 
add-commutes, 
add-swap, 
add-associates, 
minus-one-mul-top, 
zero-add, 
minus-one-mul, 
minus-add, 
condition-implies-le, 
sq_stable__le, 
not-le-2, 
false_wf, 
decidable__le, 
power-set-lift_wf, 
exists_wf, 
squash_wf, 
power-set_wf, 
all_wf, 
nat_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
lambdaFormation, 
functionEquality, 
lemma_by_obid, 
hypothesis, 
hypothesisEquality, 
thin, 
instantiate, 
sqequalHypSubstitution, 
isectElimination, 
applyEquality, 
lambdaEquality, 
cumulativity, 
universeEquality, 
sqequalRule, 
dependent_set_memberEquality, 
addEquality, 
setElimination, 
rename, 
natural_numberEquality, 
dependent_functionElimination, 
unionElimination, 
independent_pairFormation, 
voidElimination, 
productElimination, 
independent_functionElimination, 
independent_isectElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
isect_memberEquality, 
voidEquality, 
intEquality, 
because_Cache, 
minusEquality, 
dependent_pairEquality, 
dependent_pairFormation, 
multiplyEquality, 
baseApply, 
closedConclusion, 
productEquality, 
equalityTransitivity, 
equalitySymmetry
Latex:
\mforall{}[T:Type].  \mforall{}[R:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].
    ((\mforall{}x:T.  (R  x  x))
    {}\mRightarrow{}  (\mforall{}f:\mBbbN{}  {}\mrightarrow{}  P(T)
                (\mdownarrow{}\mexists{}n:\mBbbN{}
                      ((power-set-lift(T;R)  (f  (n  +  1))  (f  n))  {}\mRightarrow{}  (power-set-lift(T;R)  (f  n)  (f  (n  +  1))))))
    {}\mRightarrow{}  AFx,y:T.R[x;y])
Date html generated:
2016_05_13-PM-03_51_45
Last ObjectModification:
2016_01_14-PM-07_00_34
Theory : bar-induction
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