Nuprl Lemma : sum-is-zero
∀[n:ℕ]. ∀[f:ℕn ⟶ ℤ].  Σ(f[x] | x < n) = 0 ∈ ℤ supposing ∀i:ℕn. (f[i] = 0 ∈ ℤ)
Proof
Definitions occuring in Statement : 
sum: Σ(f[x] | x < k)
, 
int_seg: {i..j-}
, 
nat: ℕ
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
function: 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
, 
uimplies: b supposing a
, 
squash: ↓T
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
true: True
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
, 
nat: ℕ
, 
ge: i ≥ j 
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
not: ¬A
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
false: False
, 
top: Top
Lemmas referenced : 
equal_wf, 
squash_wf, 
true_wf, 
istype-universe, 
sum_functionality, 
subtype_rel_self, 
iff_weakening_equal, 
int_seg_wf, 
istype-int, 
int_subtype_base, 
nat_wf, 
sum_constant, 
nat_properties, 
decidable__equal_int, 
full-omega-unsat, 
intformnot_wf, 
intformeq_wf, 
itermMultiply_wf, 
itermConstant_wf, 
itermVar_wf, 
int_formula_prop_not_lemma, 
istype-void, 
int_formula_prop_eq_lemma, 
int_term_value_mul_lemma, 
int_term_value_constant_lemma, 
int_term_value_var_lemma, 
int_formula_prop_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
introduction, 
cut, 
applyEquality, 
thin, 
Error :lambdaEquality_alt, 
sqequalHypSubstitution, 
imageElimination, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
equalityTransitivity, 
hypothesis, 
equalitySymmetry, 
Error :universeIsType, 
Error :inhabitedIsType, 
instantiate, 
universeEquality, 
intEquality, 
sqequalRule, 
because_Cache, 
closedConclusion, 
natural_numberEquality, 
independent_isectElimination, 
Error :lambdaFormation_alt, 
dependent_functionElimination, 
imageMemberEquality, 
baseClosed, 
productElimination, 
independent_functionElimination, 
Error :functionIsType, 
setElimination, 
rename, 
Error :equalityIsType4, 
Error :isect_memberEquality_alt, 
axiomEquality, 
Error :isectIsTypeImplies, 
unionElimination, 
approximateComputation, 
Error :dependent_pairFormation_alt, 
int_eqEquality, 
voidElimination
Latex:
\mforall{}[n:\mBbbN{}].  \mforall{}[f:\mBbbN{}n  {}\mrightarrow{}  \mBbbZ{}].    \mSigma{}(f[x]  |  x  <  n)  =  0  supposing  \mforall{}i:\mBbbN{}n.  (f[i]  =  0)
Date html generated:
2019_06_20-PM-01_18_04
Last ObjectModification:
2018_10_16-PM-04_30_17
Theory : int_2
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