Nuprl Lemma : upto_equal_nil
∀[n:ℕ]. uiff(upto(n) = [] ∈ (ℤ List);n = 0 ∈ ℤ)
Proof
Definitions occuring in Statement : 
upto: upto(n)
, 
nil: []
, 
list: T List
, 
nat: ℕ
, 
uiff: uiff(P;Q)
, 
uall: ∀[x:A]. B[x]
, 
natural_number: $n
, 
int: ℤ
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
nat: ℕ
, 
int_seg: {i..j-}
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
squash: ↓T
, 
prop: ℙ
, 
label: ...$L... t
, 
true: True
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
, 
sq_type: SQType(T)
, 
all: ∀x:A. B[x]
Lemmas referenced : 
upto_is_nil, 
subtype_base_sq, 
list_wf, 
int_seg_wf, 
list_subtype_base, 
set_subtype_base, 
lelt_wf, 
int_subtype_base, 
equal_wf, 
squash_wf, 
true_wf, 
sqequal-nil, 
nil_wf, 
iff_weakening_equal, 
equal-wf-T-base, 
upto_wf, 
subtype_rel_list, 
nat_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
independent_pairFormation, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
productElimination, 
independent_isectElimination, 
instantiate, 
cumulativity, 
natural_numberEquality, 
setElimination, 
rename, 
hypothesis, 
because_Cache, 
sqequalRule, 
intEquality, 
lambdaEquality, 
applyEquality, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
universeEquality, 
imageMemberEquality, 
baseClosed, 
independent_functionElimination, 
dependent_functionElimination, 
independent_pairEquality, 
isect_memberEquality, 
axiomEquality
Latex:
\mforall{}[n:\mBbbN{}].  uiff(upto(n)  =  [];n  =  0)
Date html generated:
2017_04_17-AM-07_57_26
Last ObjectModification:
2017_02_27-PM-04_29_04
Theory : list_1
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