Nuprl Lemma : twkl!-implies-dfan
∀T:Type. ((∃k:ℕ. T ~ ℕk) 
⇒ WKL!(T) 
⇒ Fan_d(T))
Proof
Definitions occuring in Statement : 
twkl!: WKL!(T)
, 
dfan: Fan_d(T)
, 
equipollent: A ~ B
, 
int_seg: {i..j-}
, 
nat: ℕ
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
implies: P 
⇒ Q
, 
natural_number: $n
, 
universe: Type
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
dfan: Fan_d(T)
, 
dbar: dbar(T;X)
, 
and: P ∧ Q
, 
tbar: tbar(T;X)
, 
dec-predicate: Decidable(X)
, 
ubar: ubar(T;X)
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
nat: ℕ
, 
so_apply: x[s]
, 
exists: ∃x:A. B[x]
, 
le: A ≤ B
, 
less_than': less_than'(a;b)
, 
false: False
, 
not: ¬A
, 
int_seg: {i..j-}
, 
lelt: i ≤ j < k
, 
less_than: a < b
, 
squash: ↓T
, 
true: True
, 
upto: upto(n)
, 
from-upto: [n, m)
, 
ifthenelse: if b then t else f fi 
, 
lt_int: i <z j
, 
bfalse: ff
, 
top: Top
, 
subtype_rel: A ⊆r B
, 
uimplies: b supposing a
, 
guard: {T}
, 
ge: i ≥ j 
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
pi1: fst(t)
, 
compose: f o g
, 
cand: A c∧ B
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
sq_type: SQType(T)
, 
equipollent: A ~ B
, 
biject: Bij(A;B;f)
, 
surject: Surj(A;B;f)
, 
twkl!: WKL!(T)
, 
down-closed: down-closed(T;X)
, 
R-closed: R-closed(T;x.X[x];a,b.R[a; b])
, 
upwd-closure: upwd-closure(T;A)
, 
let: let, 
unbounded-list-predicate: Unbounded(A)
, 
label: ...$L... t
, 
uiff: uiff(P;Q)
, 
tree-big: tree-big(T;A;n)
, 
eff-unique-path: eff-unique-path(T;A)
, 
sq_exists: ∃x:{A| B[x]}
, 
is-path: is-path(A;f)
, 
sq_stable: SqStable(P)
, 
compat: l1 || l2
Lemmas referenced : 
nil_wf, 
tree-big-monotone, 
dbar_wf, 
list_wf, 
twkl!_wf, 
exists_wf, 
nat_wf, 
equipollent_wf, 
int_seg_wf, 
false_wf, 
le_wf, 
lelt_wf, 
map_nil_lemma, 
map_wf, 
subtype_rel_dep_function, 
int_seg_subtype_nat, 
upto_wf, 
all_wf, 
tree-big-least, 
not-tree-big, 
set_wf, 
tree-big_wf, 
upwd-closure_wf, 
not_wf, 
int_seg_properties, 
nat_properties, 
decidable__le, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformnot_wf, 
intformle_wf, 
itermConstant_wf, 
itermAdd_wf, 
itermVar_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_term_value_add_lemma, 
int_term_value_var_lemma, 
int_formula_prop_wf, 
equal_wf, 
decidable__tree-big, 
decidable__upwd-closure, 
length_wf, 
compose_wf, 
less_than_wf, 
squash_wf, 
true_wf, 
iff_weakening_equal, 
decidable__lt, 
intformless_wf, 
int_formula_prop_less_lemma, 
subtype_base_sq, 
int_subtype_base, 
add_nat_wf, 
intformeq_wf, 
int_formula_prop_eq_lemma, 
decidable__equal_int, 
non_neg_length, 
equipollent-zero, 
decidable__equal_equipollent, 
length_wf_nat, 
let_wf, 
append_wf, 
subtract_wf, 
iseg_wf, 
iseg_transitivity, 
iseg_append_iff, 
length-append, 
map-length, 
length_upto, 
le_weakening2, 
length_append, 
subtype_rel_list, 
top_wf, 
itermSubtract_wf, 
int_term_value_subtract_lemma, 
list_extensionality, 
length-map, 
select-map, 
iseg_select, 
and_wf, 
decidable__exists_length, 
decidable__not, 
not_over_exists, 
down-closed_wf, 
unbounded-list-predicate_wf, 
decidable__implies, 
decidable__and2, 
decidable__equal_list, 
imax_ub, 
imax_wf, 
iseg-map, 
int_seg_subtype, 
upto_iseg, 
select_wf, 
select-upto, 
sq_stable_from_decidable, 
decidable__exists_int_seg, 
iseg_weakening, 
iseg_length, 
common_iseg_compat, 
iseg_same_length
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
sqequalHypSubstitution, 
productElimination, 
thin, 
rename, 
cut, 
hypothesis, 
dependent_functionElimination, 
introduction, 
extract_by_obid, 
isectElimination, 
cumulativity, 
hypothesisEquality, 
unionElimination, 
functionExtensionality, 
applyEquality, 
functionEquality, 
universeEquality, 
sqequalRule, 
lambdaEquality, 
natural_numberEquality, 
setElimination, 
dependent_pairFormation, 
dependent_set_memberEquality, 
independent_pairFormation, 
because_Cache, 
imageMemberEquality, 
baseClosed, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
independent_isectElimination, 
independent_functionElimination, 
promote_hyp, 
setEquality, 
productEquality, 
addEquality, 
int_eqEquality, 
intEquality, 
computeAll, 
equalityTransitivity, 
equalitySymmetry, 
applyLambdaEquality, 
imageElimination, 
instantiate, 
addLevel, 
levelHypothesis, 
hyp_replacement, 
inlFormation, 
inrFormation
Latex:
\mforall{}T:Type.  ((\mexists{}k:\mBbbN{}.  T  \msim{}  \mBbbN{}k)  {}\mRightarrow{}  WKL!(T)  {}\mRightarrow{}  Fan\_d(T))
Date html generated:
2017_04_17-AM-09_38_44
Last ObjectModification:
2017_02_27-PM-05_43_56
Theory : fan-theorem
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