Nuprl Lemma : length-merge-int
∀[T:Type]. ∀[as,bs:T List].  (||merge-int(bs;as)|| = (||bs|| + ||as||) ∈ ℤ) supposing T ⊆r ℤ
Proof
Definitions occuring in Statement : 
length: ||as||
, 
merge-int: merge-int(as;bs)
, 
list: T List
, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
add: n + m
, 
int: ℤ
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
implies: P 
⇒ Q
, 
merge-int: merge-int(as;bs)
, 
all: ∀x:A. B[x]
, 
top: Top
, 
squash: ↓T
, 
prop: ℙ
, 
true: True
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
list_induction, 
uall_wf, 
list_wf, 
equal_wf, 
length_wf, 
merge-int_wf, 
reduce_nil_lemma, 
length_of_nil_lemma, 
add-zero, 
reduce_cons_lemma, 
length_of_cons_lemma, 
squash_wf, 
true_wf, 
length-insert-int, 
iff_weakening_equal, 
add_functionality_wrt_eq, 
general_add_assoc, 
subtype_rel_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
thin, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
sqequalRule, 
lambdaEquality, 
cumulativity, 
hypothesis, 
intEquality, 
independent_isectElimination, 
addEquality, 
independent_functionElimination, 
dependent_functionElimination, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
because_Cache, 
lambdaFormation, 
rename, 
applyEquality, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
universeEquality, 
productElimination, 
axiomEquality
Latex:
\mforall{}[T:Type].  \mforall{}[as,bs:T  List].    (||merge-int(bs;as)||  =  (||bs||  +  ||as||))  supposing  T  \msubseteq{}r  \mBbbZ{}
Date html generated:
2017_04_14-AM-08_36_13
Last ObjectModification:
2017_02_27-PM-03_28_21
Theory : list_0
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