Nuprl Lemma : length-concat
∀[ll:Top List List]. (||concat(ll)|| = l_sum(map(λl.||l||;ll)) ∈ ℤ)
Proof
Definitions occuring in Statement : 
l_sum: l_sum(L)
, 
length: ||as||
, 
concat: concat(ll)
, 
map: map(f;as)
, 
list: T List
, 
uall: ∀[x:A]. B[x]
, 
top: Top
, 
lambda: λx.A[x]
, 
int: ℤ
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
l_sum: l_sum(L)
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
so_lambda: λ2x.t[x]
, 
nat: ℕ
, 
so_apply: x[s]
, 
implies: P 
⇒ Q
, 
concat: concat(ll)
, 
all: ∀x:A. B[x]
, 
top: Top
, 
uimplies: b supposing a
, 
sq_type: SQType(T)
, 
guard: {T}
, 
prop: ℙ
Lemmas referenced : 
list_induction, 
list_wf, 
top_wf, 
equal_wf, 
length_wf, 
concat_wf, 
reduce_wf, 
nat_wf, 
map_wf, 
length_wf_nat, 
reduce_nil_lemma, 
map_nil_lemma, 
length_of_nil_lemma, 
map_cons_lemma, 
reduce_cons_lemma, 
subtype_base_sq, 
int_subtype_base, 
concat-cons, 
length-append
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
isect_memberFormation, 
cut, 
thin, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesis, 
lambdaEquality, 
intEquality, 
hypothesisEquality, 
addEquality, 
setElimination, 
rename, 
natural_numberEquality, 
independent_functionElimination, 
dependent_functionElimination, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
lambdaFormation, 
instantiate, 
cumulativity, 
independent_isectElimination, 
equalityTransitivity, 
equalitySymmetry, 
because_Cache
Latex:
\mforall{}[ll:Top  List  List].  (||concat(ll)||  =  l\_sum(map(\mlambda{}l.||l||;ll)))
Date html generated:
2016_05_14-PM-02_54_34
Last ObjectModification:
2015_12_26-PM-02_32_03
Theory : list_1
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