Nuprl Lemma : l_member-alt-def
∀[T:Type]. ∀L:T List. ∀x:T. ((x ∈ L)
⇐⇒ ∃i:ℕ||L||. (x = L[i] ∈ T))
Proof
Definitions occuring in Statement :
l_member: (x ∈ l)
,
select: L[n]
,
length: ||as||
,
list: T List
,
int_seg: {i..j-}
,
uall: ∀[x:A]. B[x]
,
all: ∀x:A. B[x]
,
exists: ∃x:A. B[x]
,
iff: P
⇐⇒ Q
,
natural_number: $n
,
universe: Type
,
equal: s = t ∈ T
Definitions unfolded in proof :
l_member: (x ∈ l)
,
uall: ∀[x:A]. B[x]
,
all: ∀x:A. B[x]
,
iff: P
⇐⇒ Q
,
and: P ∧ Q
,
implies: P
⇒ Q
,
exists: ∃x:A. B[x]
,
member: t ∈ T
,
nat: ℕ
,
int_seg: {i..j-}
,
lelt: i ≤ j < k
,
prop: ℙ
,
cand: A c∧ B
,
uimplies: b supposing a
,
guard: {T}
,
ge: i ≥ j
,
decidable: Dec(P)
,
or: P ∨ Q
,
satisfiable_int_formula: satisfiable_int_formula(fmla)
,
false: False
,
not: ¬A
,
top: Top
,
less_than: a < b
,
squash: ↓T
,
so_lambda: λ2x.t[x]
,
so_apply: x[s]
,
rev_implies: P
⇐ Q
,
subtype_rel: A ⊆r B
,
le: A ≤ B
,
less_than': less_than'(a;b)
Lemmas referenced :
lelt_wf,
equal_wf,
select_wf,
int_seg_properties,
length_wf,
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,
decidable__lt,
intformless_wf,
int_formula_prop_less_lemma,
exists_wf,
nat_wf,
less_than_wf,
int_seg_subtype_nat,
false_wf,
int_seg_wf,
list_wf
Rules used in proof :
sqequalSubstitution,
sqequalRule,
sqequalReflexivity,
sqequalTransitivity,
computationStep,
isect_memberFormation,
lambdaFormation,
independent_pairFormation,
sqequalHypSubstitution,
productElimination,
thin,
dependent_pairFormation,
setElimination,
rename,
dependent_set_memberEquality,
hypothesisEquality,
hypothesis,
cut,
introduction,
extract_by_obid,
isectElimination,
because_Cache,
addLevel,
levelHypothesis,
independent_isectElimination,
natural_numberEquality,
cumulativity,
dependent_functionElimination,
unionElimination,
lambdaEquality,
int_eqEquality,
intEquality,
isect_memberEquality,
voidElimination,
voidEquality,
computeAll,
imageElimination,
productEquality,
applyEquality,
universeEquality
Latex:
\mforall{}[T:Type]. \mforall{}L:T List. \mforall{}x:T. ((x \mmember{} L) \mLeftarrow{}{}\mRightarrow{} \mexists{}i:\mBbbN{}||L||. (x = L[i]))
Date html generated:
2017_04_17-AM-07_25_28
Last ObjectModification:
2017_02_27-PM-04_04_19
Theory : list_1
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