Nuprl Lemma : rv-circle-circle-lemma2'

r1,r2:{r:ℝr0 ≤ r} . ∀b:ℝ^2.
  ((r0 < ||b||)
   ((r1^2 r2^2) ||b||^2^2 ≤ (r(4) ||b||^2 r1^2))
   (∃u,v:ℝ^2
       (((||u|| r1) ∧ (||u b|| r2))
       ∧ ((||v|| r1) ∧ (||v b|| r2))
       ∧ (((r1^2 r2^2) ||b||^2^2 < (r(4) ||b||^2 r1^2))  (r2-left(u;b;λi.r0) ∧ r2-left(v;λi.r0;b))))))


Proof




Definitions occuring in Statement :  r2-left: r2-left(p;q;r) real-vec-norm: ||x|| real-vec-sub: Y real-vec: ^n rleq: x ≤ y rless: x < y rnexp: x^k1 rsub: y req: y rmul: b radd: b int-to-real: r(n) real: all: x:A. B[x] exists: x:A. B[x] implies:  Q and: P ∧ Q set: {x:A| B[x]}  lambda: λx.A[x] natural_number: $n
Definitions unfolded in proof :  all: x:A. B[x] member: t ∈ T nat: le: A ≤ B and: P ∧ Q less_than': less_than'(a;b) not: ¬A implies:  Q false: False uall: [x:A]. B[x] prop: dot-product: x⋅y subtract: m so_lambda: λ2x.t[x] real-vec: ^n int_seg: {i..j-} lelt: i ≤ j < k less_than: a < b squash: T rless: x < y sq_exists: x:A [B[x]] nat_plus: + decidable: Dec(P) or: P ∨ Q uimplies: supposing a satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] so_apply: x[s] bool: 𝔹 unit: Unit it: btrue: tt ifthenelse: if then else fi  bfalse: ff uiff: uiff(P;Q) sq_type: SQType(T) guard: {T} bnot: ¬bb assert: b rev_implies:  Q iff: ⇐⇒ Q eq_int: (i =z j) nequal: a ≠ b ∈  lt_int: i <j rev_uimplies: rev_uimplies(P;Q) req_int_terms: t1 ≡ t2 rneq: x ≠ y true: True rdiv: (x/y) exp: i^n primrec: primrec(n;b;c) primtailrec: primtailrec(n;i;b;f) subtype_rel: A ⊆B let: let sq_stable: SqStable(P) nonneg-poly: nonneg-poly(p) bl-all: (∀x∈L.P[x])_b reduce: reduce(f;k;as) list_ind: list_ind int_term_to_ipoly: int_term_to_ipoly(t) int_term_ind: int_term_ind itermAdd: left (+) right add_ipoly: add_ipoly(p;q) add-ipoly-prepend: add-ipoly-prepend(p;q;l) itermMultiply: left (*) right mul_ipoly: mul_ipoly(p;q) itermVar: vvar cons: [a b] cbv_list_accum: cbv_list_accum(x,a.f[x; a];y;L) nil: [] mul-mono-poly: mul-mono-poly(m;p) mul-monomials: mul-monomials(m1;m2) merge-int-accum: merge-int-accum(as;bs) eager-accum: eager-accum(x,a.f[x; a];y;l) callbyvalueall: callbyvalueall evalall: evalall(t) insert-int: insert-int(x;l) imonomial-le: imonomial-le(m1;m2) intlex: l1 ≤_lex l2 length: ||as|| pi2: snd(t) bor: p ∨bq band: p ∧b q intlex-aux: intlex-aux(l1;l2) rev-append: rev(as) bs list_accum: list_accum nonneg-monomial: nonneg-monomial(m) le_int: i ≤j even-int-list: even-int-list(L) null: null(as) tl: tl(l) hd: hd(l) pi1: fst(t) real-vec-norm: ||x|| cand: c∧ B real-vec-mul: a*X real-vec-add: Y r2-left: r2-left(p;q;r) r2-det: |pqr| real-vec-sub: Y

Latex:
\mforall{}r1,r2:\{r:\mBbbR{}|  r0  \mleq{}  r\}  .  \mforall{}b:\mBbbR{}\^{}2.
    ((r0  <  ||b||)
    {}\mRightarrow{}  ((r1\^{}2  -  r2\^{}2)  +  ||b||\^{}2\^{}2  \mleq{}  (r(4)  *  ||b||\^{}2  *  r1\^{}2))
    {}\mRightarrow{}  (\mexists{}u,v:\mBbbR{}\^{}2
              (((||u||  =  r1)  \mwedge{}  (||u  -  b||  =  r2))
              \mwedge{}  ((||v||  =  r1)  \mwedge{}  (||v  -  b||  =  r2))
              \mwedge{}  (((r1\^{}2  -  r2\^{}2)  +  ||b||\^{}2\^{}2  <  (r(4)  *  ||b||\^{}2  *  r1\^{}2))
                  {}\mRightarrow{}  (r2-left(u;b;\mlambda{}i.r0)  \mwedge{}  r2-left(v;\mlambda{}i.r0;b))))))



Date html generated: 2020_05_20-PM-01_00_12
Last ObjectModification: 2019_12_14-PM-02_58_25

Theory : reals


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