Nuprl Lemma : streamless-implies-not-not-enum
∀[T:Type]. (streamless(T) ⇒ (¬¬(∃L:T List. ∀x:T. (x ∈ L))))
Proof
Definitions occuring in Statement : 
streamless: streamless(T), 
l_member: (x ∈ l), 
list: T List, 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
exists: ∃x:A. B[x], 
not: ¬A, 
implies: P ⇒ Q, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
implies: P ⇒ Q, 
not: ¬A, 
false: False, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
all: ∀x:A. B[x], 
decidable: Dec(P), 
or: P ∨ Q, 
guard: {T}, 
prop: ℙ, 
squash: ↓T, 
top: Top, 
exists: ∃x:A. B[x], 
no_repeats: no_repeats(T;l), 
uimplies: b supposing a, 
nat: ℕ, 
ge: i ≥ j , 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
and: P ∧ Q, 
subtype_rel: A ⊆r B, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(P;Q), 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
sq_type: SQType(T), 
bnot: ¬bb, 
assert: ↑b, 
le: A ≤ B, 
less_than: a < b, 
true: True, 
iff: P ⇐⇒ Q, 
select: L[n], 
cons: [a / b], 
l_member: (x ∈ l), 
cand: A c∧ B, 
streamless: streamless(T), 
less_than': less_than'(a;b), 
rev_implies: P ⇐ Q, 
int_seg: {i..j-}, 
lelt: i ≤ j < k
Lemmas referenced : 
streamless-dec-equal, 
basic-bar-induction, 
not_wf, 
no_repeats_wf, 
list_wf, 
or_wf, 
exists_wf, 
all_wf, 
l_member_wf, 
decidable__not, 
decidable__no_repeats, 
append_wf, 
cons_wf, 
nil_wf, 
nat_wf, 
no_repeats_nil, 
streamless_wf, 
decidable__l_member, 
equal_wf, 
select_wf, 
length-append, 
length_of_cons_lemma, 
length_of_nil_lemma, 
nat_properties, 
decidable__le, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformnot_wf, 
intformle_wf, 
itermConstant_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_var_lemma, 
int_formula_prop_wf, 
less_than_wf, 
length_wf, 
subtype_rel_list, 
top_wf, 
lt_int_wf, 
bool_wf, 
eqtt_to_assert, 
assert_of_lt_int, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
length_nil, 
non_neg_length, 
length_cons, 
length_append, 
decidable__lt, 
intformless_wf, 
intformeq_wf, 
itermAdd_wf, 
int_formula_prop_less_lemma, 
int_formula_prop_eq_lemma, 
int_term_value_add_lemma, 
decidable__equal_int, 
le_wf, 
equal-wf-base, 
int_subtype_base, 
zero-add, 
subtract_wf, 
add-is-int-iff, 
itermSubtract_wf, 
int_term_value_subtract_lemma, 
false_wf, 
length-singleton, 
squash_wf, 
true_wf, 
iff_weakening_equal, 
select-append, 
imax_wf, 
add_nat_wf, 
imax_nat, 
map_wf, 
int_seg_wf, 
subtype_rel_dep_function, 
int_seg_subtype_nat, 
upto_wf, 
map-length, 
length_upto, 
ifthenelse_wf, 
le_int_wf, 
assert_of_le_int, 
add_functionality_wrt_eq, 
imax_unfold, 
lelt_wf, 
select-map, 
select-upto
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
lambdaFormation, 
thin, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
independent_functionElimination, 
hypothesis, 
because_Cache, 
sqequalRule, 
lambdaEquality, 
cumulativity, 
dependent_functionElimination, 
unionElimination, 
inrFormation, 
voidElimination, 
inlFormation, 
imageElimination, 
imageMemberEquality, 
baseClosed, 
functionEquality, 
isect_memberEquality, 
voidEquality, 
universeEquality, 
setElimination, 
rename, 
independent_isectElimination, 
natural_numberEquality, 
dependent_pairFormation, 
int_eqEquality, 
intEquality, 
independent_pairFormation, 
computeAll, 
equalityTransitivity, 
equalitySymmetry, 
applyEquality, 
equalityElimination, 
productElimination, 
promote_hyp, 
instantiate, 
dependent_set_memberEquality, 
pointwiseFunctionality, 
baseApply, 
closedConclusion, 
productEquality, 
addEquality, 
applyLambdaEquality
Latex:
\mforall{}[T:Type].  (streamless(T)  {}\mRightarrow{}  (\mneg{}\mneg{}(\mexists{}L:T  List.  \mforall{}x:T.  (x  \mmember{}  L))))
Date html generated:
2018_05_21-PM-09_02_43
Last ObjectModification:
2017_07_26-PM-06_25_36
Theory : general
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