Nuprl Lemma : firstn_factor
∀T:Type. ∀as:T List. ∀n:{0...||as||}.  (firstn(n;as) = (Π 0 ≤ i < n. [as[i]]) ∈ (T List))
Proof
Definitions occuring in Statement : 
lapp_imon: <T List,@>, 
firstn: firstn(n;as), 
select: L[n], 
length: ||as||, 
cons: [a / b], 
nil: [], 
list: T List, 
int_iseg: {i...j}, 
all: ∀x:A. B[x], 
natural_number: $n, 
universe: Type, 
equal: s = t ∈ T, 
mon_itop: Π lb ≤ i < ub. E[i]
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
so_lambda: λ2x.t[x], 
int_iseg: {i...j}, 
int_seg: {i..j-}, 
uimplies: b supposing a, 
guard: {T}, 
and: P ∧ Q, 
lelt: i ≤ j < k, 
decidable: Dec(P), 
or: P ∨ Q, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
exists: ∃x:A. B[x], 
false: False, 
implies: P ⇒ Q, 
not: ¬A, 
top: Top, 
prop: ℙ, 
le: A ≤ B, 
subtype_rel: A ⊆r B, 
so_apply: x[s], 
firstn: firstn(n;as), 
so_lambda: so_lambda(x,y,z.t[x; y; z]), 
so_apply: x[s1;s2;s3], 
select: L[n], 
nil: [], 
it: ⋅, 
so_lambda: λ2x y.t[x; y], 
so_apply: x[s1;s2], 
cand: A c∧ B, 
sq_type: SQType(T), 
mon_itop: Π lb ≤ i < ub. E[i], 
itop: Π(op,id) lb ≤ i < ub. E[i], 
ycomb: Y, 
ifthenelse: if b then t else f fi , 
lt_int: i <z j, 
bfalse: ff, 
grp_id: e, 
pi1: fst(t), 
pi2: snd(t), 
lapp_imon: <T List,@>, 
bool: 𝔹, 
unit: Unit, 
btrue: tt, 
uiff: uiff(P;Q), 
true: True, 
ge: i ≥ j , 
grp_car: |g|, 
imon: IMonoid, 
squash: ↓T, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q, 
infix_ap: x f y, 
grp_op: *, 
append: as @ bs, 
subtract: n - m
Lemmas referenced : 
list_induction, 
all_wf, 
int_iseg_wf, 
length_wf, 
equal_wf, 
list_wf, 
firstn_wf, 
mon_itop_wf, 
lapp_imon_wf, 
cons_wf, 
select_wf, 
int_seg_properties, 
int_iseg_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, 
nil_wf, 
int_seg_wf, 
length_of_nil_lemma, 
list_ind_nil_lemma, 
stuck-spread, 
base_wf, 
length_of_cons_lemma, 
subtype_base_sq, 
set_subtype_base, 
le_wf, 
int_subtype_base, 
decidable__equal_int, 
intformeq_wf, 
int_formula_prop_eq_lemma, 
lt_int_wf, 
bool_wf, 
assert_wf, 
less_than_wf, 
le_int_wf, 
bnot_wf, 
uiff_transitivity, 
eqtt_to_assert, 
assert_of_lt_int, 
list_ind_cons_lemma, 
eqff_to_assert, 
assert_functionality_wrt_uiff, 
bnot_of_lt_int, 
assert_of_le_int, 
subtract_wf, 
itermSubtract_wf, 
int_term_value_subtract_lemma, 
add-is-int-iff, 
itermAdd_wf, 
int_term_value_add_lemma, 
false_wf, 
non_neg_length, 
grp_car_wf, 
imon_wf, 
squash_wf, 
true_wf, 
iff_weakening_equal, 
mon_itop_unroll_lo, 
grp_op_wf, 
select_cons_hd, 
select_cons_tl, 
mon_itop_shift, 
minus-minus, 
add-associates, 
add-swap, 
add-commutes, 
zero-add
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
thin, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
sqequalRule, 
lambdaEquality, 
natural_numberEquality, 
cumulativity, 
hypothesis, 
because_Cache, 
setElimination, 
rename, 
dependent_functionElimination, 
independent_isectElimination, 
productElimination, 
unionElimination, 
dependent_pairFormation, 
int_eqEquality, 
intEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
independent_pairFormation, 
computeAll, 
applyEquality, 
independent_functionElimination, 
baseClosed, 
addEquality, 
universeEquality, 
instantiate, 
productEquality, 
dependent_set_memberEquality, 
equalityTransitivity, 
equalitySymmetry, 
equalityElimination, 
pointwiseFunctionality, 
promote_hyp, 
baseApply, 
closedConclusion, 
imageElimination, 
imageMemberEquality, 
functionEquality, 
minusEquality
Latex:
\mforall{}T:Type.  \mforall{}as:T  List.  \mforall{}n:\{0...||as||\}.    (firstn(n;as)  =  (\mPi{}  0  \mleq{}  i  <  n.  [as[i]]))
Date html generated:
2017_10_01-AM-09_57_32
Last ObjectModification:
2017_03_03-PM-00_59_25
Theory : list_2
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