Nuprl Lemma : wellfounded-llex-ext
∀[A:Type]. ∀[<:A ⟶ A ⟶ ℙ].
  ((∀a,b:A.  SqStable(<[a;b]))
  ⇒ WellFnd{i}(A;a,b.<[a;b])
  ⇒ WellFnd{i}(Des(A;a,b.<[a;b]);L1,L2.L1 llex(A;a,b.<[a;b]) L2))
Proof
Definitions occuring in Statement : 
llex: llex(A;a,b.<[a; b]), 
Des: Des(A;a,b.<[a; b]), 
wellfounded: WellFnd{i}(A;x,y.R[x; y]), 
sq_stable: SqStable(P), 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
infix_ap: x f y, 
so_apply: x[s1;s2], 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
function: x:A ⟶ B[x], 
universe: Type
Definitions unfolded in proof : 
member: t ∈ T, 
btrue: tt, 
it: ⋅, 
bfalse: ff, 
spreadn: let a,b,c,d,e = u in v[a; b; c; d; e], 
spreadn: spread4, 
wellfounded-llex, 
list-cases, 
any: any x, 
llex-append1, 
decidable__lt, 
colist-cases, 
iff_weakening_equal, 
iseg_select, 
decidable__le, 
decidable__squash, 
decidable__and, 
decidable__less_than', 
colist-ext, 
list_induction, 
nil_iseg, 
cons_iseg, 
decidable__not, 
decidable_functionality, 
squash_elim, 
sq_stable_from_decidable, 
decidable__implies, 
decidable__false, 
iff_preserves_decidability, 
sq_stable__from_stable, 
stable__from_decidable, 
uall: ∀[x:A]. B[x], 
so_lambda: so_lambda(x,y,z,w.t[x; y; z; w]), 
so_apply: x[s1;s2;s3;s4], 
so_lambda: λ2x.t[x], 
top: Top, 
so_apply: x[s], 
uimplies: b supposing a, 
so_lambda: λ2x y.t[x; y], 
so_apply: x[s1;s2], 
length: ||as||, 
list_ind: list_ind, 
nil: [], 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
has-value: (a)↓, 
prop: ℙ
Lemmas referenced : 
wellfounded-llex, 
lifting-strict-decide, 
strict4-decide, 
lifting-strict-isaxiom, 
lifting-strict-spread, 
lifting-strict-less, 
strict4-spread, 
top_wf, 
equal_wf, 
has-value_wf_base, 
is-exception_wf, 
list-cases, 
llex-append1, 
decidable__lt, 
colist-cases, 
iff_weakening_equal, 
iseg_select, 
decidable__le, 
decidable__squash, 
decidable__and, 
decidable__less_than', 
colist-ext, 
list_induction, 
nil_iseg, 
cons_iseg, 
decidable__not, 
decidable_functionality, 
squash_elim, 
sq_stable_from_decidable, 
decidable__implies, 
decidable__false, 
iff_preserves_decidability, 
sq_stable__from_stable, 
stable__from_decidable
Rules used in proof : 
introduction, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
cut, 
instantiate, 
extract_by_obid, 
hypothesis, 
sqequalRule, 
thin, 
sqequalHypSubstitution, 
equalityTransitivity, 
equalitySymmetry, 
isectElimination, 
baseClosed, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
independent_isectElimination, 
lambdaFormation, 
sqequalSqle, 
divergentSqle, 
callbyvalueSpread, 
productEquality, 
productElimination, 
sqleReflexivity, 
hypothesisEquality, 
dependent_functionElimination, 
independent_functionElimination, 
spreadExceptionCases, 
axiomSqleEquality, 
exceptionSqequal, 
baseApply, 
closedConclusion
Latex:
\mforall{}[A:Type].  \mforall{}[<:A  {}\mrightarrow{}  A  {}\mrightarrow{}  \mBbbP{}].
    ((\mforall{}a,b:A.    SqStable(<[a;b]))
    {}\mRightarrow{}  WellFnd\{i\}(A;a,b.<[a;b])
    {}\mRightarrow{}  WellFnd\{i\}(Des(A;a,b.<[a;b]);L1,L2.L1  llex(A;a,b.<[a;b])  L2))
Date html generated:
2018_05_21-PM-07_20_05
Last ObjectModification:
2018_05_19-PM-04_47_37
Theory : general
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