Nuprl Lemma : add-remove-nth
∀[T:Type]. ∀[L:T List]. ∀[n:ℕ||L||].  (let x,L' = remove-nth(n;L) in add-nth(n;x;L') ~ L)
Proof
Definitions occuring in Statement : 
add-nth: add-nth(n;x;L)
, 
remove-nth: remove-nth(n;L)
, 
length: ||as||
, 
list: T List
, 
int_seg: {i..j-}
, 
uall: ∀[x:A]. B[x]
, 
spread: spread def, 
natural_number: $n
, 
universe: Type
, 
sqequal: s ~ t
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
nat: ℕ
, 
implies: P 
⇒ Q
, 
false: False
, 
ge: i ≥ j 
, 
uimplies: b supposing a
, 
not: ¬A
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
top: Top
, 
and: P ∧ Q
, 
prop: ℙ
, 
or: P ∨ Q
, 
cons: [a / b]
, 
le: A ≤ B
, 
less_than': less_than'(a;b)
, 
colength: colength(L)
, 
nil: []
, 
it: ⋅
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
sq_type: SQType(T)
, 
guard: {T}
, 
less_than: a < b
, 
squash: ↓T
, 
so_lambda: λ2x y.t[x; y]
, 
so_apply: x[s1;s2]
, 
decidable: Dec(P)
, 
subtype_rel: A ⊆r B
, 
lelt: i ≤ j < k
, 
int_seg: {i..j-}
, 
remove-nth: remove-nth(n;L)
, 
add-nth: add-nth(n;x;L)
, 
firstn: firstn(n;as)
, 
nth_tl: nth_tl(n;as)
, 
so_lambda: so_lambda(x,y,z.t[x; y; z])
, 
so_apply: x[s1;s2;s3]
, 
bool: 𝔹
, 
unit: Unit
, 
btrue: tt
, 
uiff: uiff(P;Q)
, 
ifthenelse: if b then t else f fi 
, 
append: as @ bs
, 
bfalse: ff
, 
bnot: ¬bb
, 
assert: ↑b
, 
rev_implies: P 
⇐ Q
, 
iff: P 
⇐⇒ Q
, 
select: L[n]
, 
subtract: n - m
, 
le_int: i ≤z j
, 
lt_int: i <z j
Lemmas referenced : 
nat_properties, 
full-omega-unsat, 
intformand_wf, 
intformle_wf, 
itermConstant_wf, 
itermVar_wf, 
intformless_wf, 
istype-int, 
int_formula_prop_and_lemma, 
istype-void, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_term_value_var_lemma, 
int_formula_prop_less_lemma, 
int_formula_prop_wf, 
ge_wf, 
less_than_wf, 
int_seg_wf, 
length_wf, 
list-cases, 
product_subtype_list, 
colength-cons-not-zero, 
colength_wf_list, 
le_wf, 
subtract-1-ge-0, 
subtype_base_sq, 
nat_wf, 
set_subtype_base, 
int_subtype_base, 
spread_cons_lemma, 
decidable__equal_int, 
subtract_wf, 
intformnot_wf, 
intformeq_wf, 
itermSubtract_wf, 
itermAdd_wf, 
int_formula_prop_not_lemma, 
int_formula_prop_eq_lemma, 
int_term_value_subtract_lemma, 
int_term_value_add_lemma, 
decidable__le, 
list_wf, 
nil_wf, 
int_seg_properties, 
length_of_nil_lemma, 
length_of_cons_lemma, 
list_ind_cons_lemma, 
reduce_tl_cons_lemma, 
lt_int_wf, 
eqtt_to_assert, 
assert_of_lt_int, 
le_int_wf, 
assert_of_le_int, 
non_neg_length, 
eqff_to_assert, 
bool_cases_sqequal, 
bool_wf, 
bool_subtype_base, 
assert-bnot, 
iff_weakening_uiff, 
assert_wf, 
list_ind_nil_lemma, 
general_arith_equation1, 
lelt_wf, 
false_wf, 
add-is-int-iff, 
decidable__lt, 
select-cons-tl
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
introduction, 
cut, 
thin, 
Error :lambdaFormation_alt, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
hypothesis, 
setElimination, 
rename, 
intWeakElimination, 
natural_numberEquality, 
independent_isectElimination, 
approximateComputation, 
independent_functionElimination, 
Error :dependent_pairFormation_alt, 
Error :lambdaEquality_alt, 
int_eqEquality, 
dependent_functionElimination, 
Error :isect_memberEquality_alt, 
voidElimination, 
sqequalRule, 
independent_pairFormation, 
Error :universeIsType, 
axiomSqEquality, 
Error :functionIsTypeImplies, 
Error :inhabitedIsType, 
unionElimination, 
promote_hyp, 
hypothesis_subsumption, 
productElimination, 
Error :equalityIsType1, 
because_Cache, 
Error :dependent_set_memberEquality_alt, 
instantiate, 
cumulativity, 
intEquality, 
equalityTransitivity, 
equalitySymmetry, 
imageElimination, 
applyLambdaEquality, 
Error :equalityIsType4, 
addEquality, 
applyEquality, 
universeEquality, 
voidEquality, 
isect_memberEquality, 
lambdaEquality, 
dependent_pairFormation, 
isect_memberFormation, 
equalityElimination, 
baseClosed, 
closedConclusion, 
baseApply, 
pointwiseFunctionality, 
dependent_set_memberEquality
Latex:
\mforall{}[T:Type].  \mforall{}[L:T  List].  \mforall{}[n:\mBbbN{}||L||].    (let  x,L'  =  remove-nth(n;L)  in  add-nth(n;x;L')  \msim{}  L)
Date html generated:
2019_06_20-PM-01_33_04
Last ObjectModification:
2018_10_03-PM-11_01_00
Theory : list_1
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