Nuprl Lemma : mem_iff_count_nzero
∀s:DSet. ∀a:|s|. ∀bs:|s| List.  (↑(a ∈b bs) ⇐⇒ (a #∈ bs) > 0)
Proof
Definitions occuring in Statement : 
count: a #∈ as, 
mem: a ∈b as, 
list: T List, 
assert: ↑b, 
gt: i > j, 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
natural_number: $n, 
dset: DSet, 
set_car: |p|
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
so_lambda: λ2x.t[x], 
dset: DSet, 
so_apply: x[s], 
implies: P ⇒ Q, 
top: Top, 
assert: ↑b, 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
prop: ℙ, 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
false: False, 
rev_implies: P ⇐ Q, 
gt: i > j, 
less_than: a < b, 
squash: ↓T, 
less_than': less_than'(a;b), 
infix_ap: x f y, 
or: P ∨ Q, 
uiff: uiff(P;Q), 
uimplies: b supposing a, 
b2i: b2i(b), 
ge: i ≥ j , 
decidable: Dec(P), 
le: A ≤ B, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
exists: ∃x:A. B[x], 
not: ¬A, 
guard: {T}, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt
Lemmas referenced : 
list_induction, 
iff_wf, 
assert_wf, 
mem_wf, 
gt_wf, 
count_wf, 
list_wf, 
set_car_wf, 
mem_nil_lemma, 
count_nil_lemma, 
mem_cons_lemma, 
count_cons_lemma, 
dset_wf, 
false_wf, 
bor_wf, 
set_eq_wf, 
or_wf, 
equal_wf, 
b2i_wf, 
iff_transitivity, 
iff_weakening_uiff, 
assert_of_bor, 
assert_of_dset_eq, 
bool_wf, 
equal-wf-T-base, 
non_neg_length, 
count_bounds, 
decidable__lt, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformnot_wf, 
intformless_wf, 
itermConstant_wf, 
itermAdd_wf, 
itermVar_wf, 
intformle_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_less_lemma, 
int_term_value_constant_lemma, 
int_term_value_add_lemma, 
int_term_value_var_lemma, 
int_formula_prop_le_lemma, 
int_formula_prop_wf, 
bnot_wf, 
not_wf, 
add-is-int-iff, 
uiff_transitivity, 
eqtt_to_assert, 
eqff_to_assert, 
assert_of_bnot
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
thin, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
because_Cache, 
sqequalRule, 
lambdaEquality, 
dependent_functionElimination, 
hypothesisEquality, 
hypothesis, 
natural_numberEquality, 
setElimination, 
rename, 
independent_functionElimination, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
independent_pairFormation, 
imageElimination, 
productElimination, 
applyEquality, 
addEquality, 
addLevel, 
impliesFunctionality, 
orFunctionality, 
independent_isectElimination, 
equalityTransitivity, 
equalitySymmetry, 
baseClosed, 
unionElimination, 
dependent_pairFormation, 
int_eqEquality, 
intEquality, 
computeAll, 
inlFormation, 
inrFormation, 
pointwiseFunctionality, 
promote_hyp, 
baseApply, 
closedConclusion, 
equalityElimination
Latex:
\mforall{}s:DSet.  \mforall{}a:|s|.  \mforall{}bs:|s|  List.    (\muparrow{}(a  \mmember{}\msubb{}  bs)  \mLeftarrow{}{}\mRightarrow{}  (a  \#\mmember{}  bs)  >  0)
Date html generated:
2017_10_01-AM-09_56_21
Last ObjectModification:
2017_03_03-PM-00_57_55
Theory : list_2
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