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: uimplies: 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: equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a squash: T prop: so_lambda: λ2x.t[x] so_apply: x[s] all: x:A. B[x] true: True subtype_rel: A ⊆B guard: {T} iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q implies:  Q nat: ge: i ≥  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


Home Index