Nuprl Lemma : W-uwellfounded_witness
λF.fix(F) ∈ ∀[A:Type]. ∀[B:A ⟶ Type].  uWellFnd(W(A;a.B[a]);w1,w2.w1 <  w2)
Proof
Definitions occuring in Statement : 
Wcmp: Wcmp(A;a.B[a];leq), 
W: W(A;a.B[a]), 
bfalse: ff, 
uwellfounded: uWellFnd(A;x,y.R[x; y]), 
uall: ∀[x:A]. B[x], 
infix_ap: x f y, 
so_apply: x[s], 
member: t ∈ T, 
fix: fix(F), 
lambda: λx.A[x], 
function: x:A ⟶ B[x], 
universe: Type
Definitions unfolded in proof : 
uwellfounded: uWellFnd(A;x,y.R[x; y]), 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
all: ∀x:A. B[x], 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
prop: ℙ, 
implies: P ⇒ Q, 
subtype_rel: A ⊆r B, 
infix_ap: x f y, 
uimplies: b supposing a, 
Wcmp: Wcmp(A;a.B[a];leq), 
Wsup: Wsup(a;b), 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
exists: ∃x:A. B[x], 
and: P ∧ Q, 
nat: ℕ, 
pcw-pp-barred: Barred(pp), 
int_seg: {i..j-}, 
lelt: i ≤ j < k, 
decidable: Dec(P), 
or: P ∨ Q, 
iff: P ⇐⇒ Q, 
not: ¬A, 
rev_implies: P ⇐ Q, 
false: False, 
uiff: uiff(P;Q), 
subtract: n - m, 
top: Top, 
le: A ≤ B, 
less_than': less_than'(a;b), 
true: True, 
cw-step: cw-step(A;a.B[a]), 
pcw-step: pcw-step(P;p.A[p];p,a.B[p; a];p,a,b.C[p; a; b]), 
spreadn: spread3, 
less_than: a < b, 
squash: ↓T, 
isr: isr(x), 
assert: ↑b, 
btrue: tt, 
ext-eq: A ≡ B, 
unit: Unit, 
it: ⋅, 
so_lambda: λ2x y.t[x; y], 
so_apply: x[s1;s2], 
so_lambda: so_lambda(x,y,z.t[x; y; z]), 
so_apply: x[s1;s2;s3], 
ext-family: F ≡ G, 
pi1: fst(t), 
nat_plus: ℕ+, 
guard: {T}, 
W-rel: W-rel(A;a.B[a];w), 
param-W-rel: param-W-rel(P;p.A[p];p,a.B[p; a];p,a,b.C[p; a; b];par;w), 
pcw-steprel: StepRel(s1;s2), 
pi2: snd(t), 
isl: isl(x), 
pcw-step-agree: StepAgree(s;p1;w), 
cand: A c∧ B, 
sq_type: SQType(T), 
sq_stable: SqStable(P)
Lemmas referenced : 
W_wf, 
isect_wf, 
infix_ap_wf, 
Wcmp_wf, 
bfalse_wf, 
void_wf, 
Wleq_weakening2, 
Wsup_wf, 
W-elimination-facts, 
int_seg_wf, 
subtract_wf, 
decidable__le, 
false_wf, 
not-le-2, 
less-iff-le, 
condition-implies-le, 
minus-one-mul, 
zero-add, 
minus-one-mul-top, 
nat_wf, 
minus-add, 
minus-minus, 
add-associates, 
add-swap, 
add-commutes, 
add_functionality_wrt_le, 
add-zero, 
le-add-cancel, 
decidable__lt, 
not-lt-2, 
add-mul-special, 
zero-mul, 
le-add-cancel-alt, 
lelt_wf, 
top_wf, 
less_than_wf, 
true_wf, 
equal_wf, 
add-subtract-cancel, 
W-ext, 
param-co-W-ext, 
unit_wf2, 
it_wf, 
param-co-W_wf, 
ext-eq_inversion, 
subtype_rel_weakening, 
assert_wf, 
btrue_wf, 
pcw-steprel_wf, 
subtype_rel_dep_function, 
subtype_base_sq, 
set_subtype_base, 
le_wf, 
int_subtype_base, 
decidable__int_equal, 
not-equal-2, 
minus-zero, 
le-add-cancel2, 
int_seg_subtype, 
sq_stable__le, 
Wcmp_transitivity, 
set_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
isect_memberEquality, 
cut, 
lambdaFormation, 
rename, 
thin, 
sqequalHypSubstitution, 
dependent_functionElimination, 
hypothesisEquality, 
equalityTransitivity, 
hypothesis, 
equalitySymmetry, 
introduction, 
extract_by_obid, 
isectElimination, 
cumulativity, 
lambdaEquality, 
applyEquality, 
functionExtensionality, 
because_Cache, 
functionEquality, 
isectEquality, 
setEquality, 
instantiate, 
universeEquality, 
setElimination, 
voidElimination, 
independent_functionElimination, 
independent_isectElimination, 
productElimination, 
strong_bar_Induction, 
natural_numberEquality, 
dependent_set_memberEquality, 
independent_pairFormation, 
unionElimination, 
addEquality, 
voidEquality, 
minusEquality, 
intEquality, 
lessCases, 
isect_memberFormation, 
sqequalAxiom, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
axiomEquality, 
int_eqReduceTrueSq, 
promote_hyp, 
hypothesis_subsumption, 
equalityElimination, 
dependent_pairEquality, 
productEquality, 
inlEquality, 
unionEquality, 
hyp_replacement, 
applyLambdaEquality
Latex:
\mlambda{}F.fix(F)  \mmember{}  \mforall{}[A:Type].  \mforall{}[B:A  {}\mrightarrow{}  Type].    uWellFnd(W(A;a.B[a]);w1,w2.w1  <    w2)
Date html generated:
2017_04_14-AM-07_43_57
Last ObjectModification:
2017_02_27-PM-03_14_58
Theory : co-recursion
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