Nuprl Lemma : i-member-proper-iff

I:Interval. (iproper(I)  (∀r:ℝ(r ∈ ⇐⇒ ∃n:ℕ+(iproper(i-approx(I;n)) ∧ (r ∈ i-approx(I;n))))))


Proof




Definitions occuring in Statement :  i-approx: i-approx(I;n) i-member: r ∈ I iproper: iproper(I) interval: Interval real: nat_plus: + all: x:A. B[x] exists: x:A. B[x] iff: ⇐⇒ Q implies:  Q and: P ∧ Q
Definitions unfolded in proof :  all: x:A. B[x] implies:  Q member: t ∈ T int_upper: {i...} uall: [x:A]. B[x] subtype_rel: A ⊆B decidable: Dec(P) or: P ∨ Q false: False nat_plus: + guard: {T} uimplies: supposing a not: ¬A satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] and: P ∧ Q prop: interval: Interval i-approx: i-approx(I;n) i-member: r ∈ I iff: ⇐⇒ Q rless: x < y sq_exists: x:A [B[x]] cand: c∧ B rccint: [l, u] rev_implies:  Q iproper: iproper(I) left-endpoint: left-endpoint(I) pi1: fst(t) endpoints: endpoints(I) outl: outl(x) right-endpoint: right-endpoint(I) pi2: snd(t) i-finite: i-finite(I) isl: isl(x) assert: b ifthenelse: if then else fi  btrue: tt true: True rneq: x ≠ y so_lambda: λ2x.t[x] so_apply: x[s] rge: x ≥ y uiff: uiff(P;Q) req_int_terms: t1 ≡ t2 bool: 𝔹 unit: Unit it: rev_uimplies: rev_uimplies(P;Q) bfalse: ff sq_type: SQType(T) bnot: ¬bb real: sq_stable: SqStable(P) squash: T rdiv: (x/y) le: A ≤ B less_than': less_than'(a;b) less_than: a < b rgt: x > y

Latex:
\mforall{}I:Interval
    (iproper(I)  {}\mRightarrow{}  (\mforall{}r:\mBbbR{}.  (r  \mmember{}  I  \mLeftarrow{}{}\mRightarrow{}  \mexists{}n:\mBbbN{}\msupplus{}.  (iproper(i-approx(I;n))  \mwedge{}  (r  \mmember{}  i-approx(I;n))))))



Date html generated: 2020_05_20-AM-11_32_26
Last ObjectModification: 2020_01_06-PM-00_58_45

Theory : reals


Home Index