Nuprl Lemma : geometric-series-one-half

We have  Σn.(r1/r(2)^n) r(2) because 0 ∈ ℤ is included in the series.⋅

Σn.(r1/r(2)^n) r(2)


Proof




Definitions occuring in Statement :  series-sum: Σn.x[n] a rdiv: (x/y) rnexp: x^k1 int-to-real: r(n) natural_number: $n
Definitions unfolded in proof :  all: x:A. B[x] so_lambda: λ2x.t[x] member: t ∈ T uall: [x:A]. B[x] uimplies: supposing a rneq: x ≠ y guard: {T} or: P ∨ Q iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q implies:  Q less_than: a < b squash: T less_than': less_than'(a;b) true: True prop: so_apply: x[s] rat_term_to_real: rat_term_to_real(f;t) rtermConstant: "const" rat_term_ind: rat_term_ind pi1: fst(t) rtermDivide: num "/" denom rtermSubtract: left "-" right pi2: snd(t) cand: c∧ B nat_plus: + decidable: Dec(P) not: ¬A satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] top: Top false: False uiff: uiff(P;Q) le: A ≤ B subtype_rel: A ⊆B rsub: y rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced :  series-sum_functionality rnexp_wf rdiv_wf int-to-real_wf rless-int rless_wf istype-nat rsub_wf assert-rat-term-eq2 rtermDivide_wf rtermConstant_wf rtermSubtract_wf istype-int geometric-series-converges rleq-int-fractions2 decidable__lt full-omega-unsat intformnot_wf intformless_wf itermConstant_wf int_formula_prop_not_lemma istype-void int_formula_prop_less_lemma int_term_value_constant_lemma int_formula_prop_wf istype-less_than istype-false rless-int-fractions3 rleq_wf rnexp-positive rmul_preserves_rless radd_wf rminus_wf rmul_wf iff_transitivity squash_wf true_wf real_wf rminus-int iff_weakening_equal rless_functionality req_weakening radd-int radd_functionality rminus_functionality rmul-rdiv-cancel rmul_comm rmul-one-both req_transitivity rmul-distrib rmul_over_rminus rmul-int req_functionality req_inversion rnexp-rdiv rnexp-one rdiv_functionality
Rules used in proof :  cut introduction extract_by_obid sqequalHypSubstitution sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity dependent_functionElimination thin sqequalRule lambdaEquality_alt isectElimination hypothesisEquality closedConclusion natural_numberEquality hypothesis independent_isectElimination inrFormation_alt because_Cache productElimination independent_functionElimination independent_pairFormation imageMemberEquality baseClosed universeIsType lambdaFormation_alt approximateComputation dependent_set_memberEquality_alt unionElimination dependent_pairFormation_alt isect_memberEquality_alt voidElimination productIsType inrFormation minusEquality addEquality multiplyEquality addLevel applyEquality lambdaEquality imageElimination equalityTransitivity equalitySymmetry universeEquality lambdaFormation levelHypothesis

Latex:
\mSigma{}n.(r1/r(2)\^{}n)  =  r(2)



Date html generated: 2019_10_29-AM-10_26_25
Last ObjectModification: 2019_04_02-AM-10_00_34

Theory : reals


Home Index