Nuprl Lemma : list_extensionality_iff
∀[T:Type]. ∀[a,b:T List].  (a = b ∈ (T List) ⇐⇒ (||a|| = ||b|| ∈ ℤ) ∧ (∀i:ℕ||a||. (a[i] = b[i] ∈ T)))
Proof
Definitions occuring in Statement : 
select: L[n], 
length: ||as||, 
list: T List, 
int_seg: {i..j-}, 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
natural_number: $n, 
int: ℤ, 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
implies: P ⇒ Q, 
member: t ∈ T, 
squash: ↓T, 
true: True, 
all: ∀x:A. B[x], 
prop: ℙ, 
rev_implies: P ⇐ Q, 
so_lambda: λ2x.t[x], 
int_seg: {i..j-}, 
uimplies: b supposing a, 
guard: {T}, 
lelt: i ≤ j < k, 
decidable: Dec(P), 
or: P ∨ Q, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
exists: ∃x:A. B[x], 
false: False, 
not: ¬A, 
top: Top, 
so_apply: x[s], 
less_than: a < b, 
nat: ℕ, 
le: A ≤ B, 
ge: i ≥ j , 
subtype_rel: A ⊆r B
Lemmas referenced : 
length_wf, 
int_seg_wf, 
equal_wf, 
list_wf, 
all_wf, 
select_wf, 
int_seg_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, 
intformeq_wf, 
int_formula_prop_eq_lemma, 
less_than_wf, 
list_extensionality, 
squash_wf, 
true_wf, 
lelt_wf, 
nat_properties, 
iff_weakening_equal, 
nat_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
independent_pairFormation, 
lambdaFormation, 
cut, 
applyEquality, 
thin, 
lambdaEquality, 
sqequalHypSubstitution, 
imageElimination, 
introduction, 
extract_by_obid, 
isectElimination, 
because_Cache, 
hypothesis, 
hypothesisEquality, 
equalitySymmetry, 
natural_numberEquality, 
sqequalRule, 
imageMemberEquality, 
baseClosed, 
cumulativity, 
productElimination, 
productEquality, 
setElimination, 
rename, 
independent_isectElimination, 
equalityTransitivity, 
dependent_functionElimination, 
unionElimination, 
dependent_pairFormation, 
int_eqEquality, 
intEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
computeAll, 
universeEquality, 
dependent_set_memberEquality, 
hyp_replacement, 
applyLambdaEquality, 
independent_functionElimination
Latex:
\mforall{}[T:Type].  \mforall{}[a,b:T  List].    (a  =  b  \mLeftarrow{}{}\mRightarrow{}  (||a||  =  ||b||)  \mwedge{}  (\mforall{}i:\mBbbN{}||a||.  (a[i]  =  b[i])))
Date html generated:
2017_04_14-AM-09_24_54
Last ObjectModification:
2017_02_27-PM-03_59_23
Theory : list_1
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