Nuprl Lemma : rv-compass-compass-lemma

∀a,b,c,d:ℝ^2.
  (a ≠ c
  ⇒ (↓∃p,q:ℝ^2. (((d(a;b) = d(a;p)) ∧ (d(c;d) = d(c;q))) ∧ (d(c;p) ≤ d(c;d)) ∧ (d(a;q) ≤ d(a;b))))
  ⇒ (∃u,v:{p:ℝ^2| ab=ap ∧ cd=cp} 
       ((↓∃p,q:ℝ^2. (((d(a;b) = d(a;p)) ∧ (d(c;d) = d(c;q))) ∧ (d(c;p) < d(c;d)) ∧ (d(a;q) < d(a;b))))
       ⇒ (r2-left(u;c;a) ∧ r2-left(v;a;c)))))


Proof




Definitions occuring in Statement :  r2-left: r2-left(p;q;r),  real-vec-sep: a ≠ b,  rv-congruent: ab=cd,  real-vec-dist: d(x;y),  real-vec: ℝ^n,  rleq: x ≤ y,  rless: x < y,  req: x = y,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  squash: ↓T,  implies: P ⇒ Q,  and: P ∧ Q,  set: {x:A| B[x]} ,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  real-vec-dist: d(x;y),  prop: ℙ,  nat: ℕ,  le: A ≤ B,  and: P ∧ Q,  less_than': less_than'(a;b),  false: False,  not: ¬A,  so_lambda: λ2x.t[x],  subtype_rel: A ⊆r B,  so_apply: x[s],  rless: x < y,  sq_exists: ∃x:{A| B[x]},  real-vec-sep: a ≠ b,  uimplies: b supposing a,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q),  squash: ↓T,  sq_stable: SqStable(P),  exists: ∃x:A. B[x],  true: True,  guard: {T},  rge: x ≥ y,  cand: A c∧ B,  req_int_terms: t1 ≡ t2,  top: Top,  rv-congruent: ab=cd,  real-vec-add: X + Y,  real-vec-sub: X - Y,  req-vec: req-vec(n;x;y),  real-vec: ℝ^n,  nat_plus: ℕ+,  less_than: a < b,  or: P ∨ Q,  r2-left: r2-left(p;q;r),  r2-det: |pqr|,  int_seg: {i..j-},  lelt: i ≤ j < k
Lemmas referenced :  rv-circle-circle-lemma2',  real-vec-dist_wf,  real-vec-sub_wf,  squash_wf,  exists_wf,  real-vec_wf,  false_wf,  le_wf,  req_wf,  real_wf,  rleq_wf,  int-to-real_wf,  real-vec-sep_wf,  rnexp_wf,  radd_wf,  rsub_wf,  rmul_wf,  rless_functionality,  req_weakening,  real-vec-dist-symmetry,  rleq_functionality,  rnexp_functionality,  radd_functionality,  rsub_functionality,  rmul_functionality,  sq_stable__rleq,  rnexp-rleq,  real-vec-dist-nonneg,  real-vec-triangle-inequality,  true_wf,  radd_comm_eq,  iff_weakening_equal,  rleq_functionality_wrt_implies,  rleq_weakening_equal,  radd_functionality_wrt_rleq,  rabs_wf,  zero-rleq-rabs,  rabs-difference-bound-rleq,  radd-preserves-rleq,  radd_comm,  itermSubtract_wf,  itermAdd_wf,  itermVar_wf,  req-iff-rsub-is-0,  real_polynomial_null,  real_term_value_sub_lemma,  real_term_value_add_lemma,  real_term_value_var_lemma,  real_term_value_const_lemma,  rnexp2-nonneg,  req_inversion,  rabs-rnexp,  rabs-of-nonneg,  rminus_wf,  radd-rminus-both,  itermMinus_wf,  req_transitivity,  rminus_functionality,  real_term_value_minus_lemma,  equal_wf,  itermMultiply_wf,  itermConstant_wf,  rnexp2,  real_term_value_mul_lemma,  req_functionality,  rleq-implies-rleq,  rmul-nonneg-case1,  radd-zero,  real-vec-add_wf,  rv-congruent_wf,  rless_wf,  r2-left_wf,  int_seg_wf,  real-vec-norm_wf,  real-vec-norm_functionality,  sq_stable__rless,  rnexp-rless,  less_than_wf,  radd-rminus-assoc,  radd-preserves-rless,  rless_transitivity2,  rabs-difference-bound-iff,  rless_functionality_wrt_implies,  rless-implies-rless,  rmul-is-positive,  rless_transitivity1,  rleq_weakening,  r2-det_wf,  lelt_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  isectElimination,  because_Cache,  hypothesisEquality,  hypothesis,  independent_functionElimination,  dependent_set_memberEquality,  natural_numberEquality,  sqequalRule,  independent_pairFormation,  lambdaEquality,  productEquality,  applyEquality,  setElimination,  rename,  setEquality,  independent_isectElimination,  productElimination,  imageElimination,  imageMemberEquality,  baseClosed,  equalityTransitivity,  equalitySymmetry,  universeEquality,  approximateComputation,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  dependent_pairFormation,  functionEquality,  inlFormation,  promote_hyp

Latex:
\mforall{}a,b,c,d:\mBbbR{}\^{}2.
    (a  \mneq{}  c
    {}\mRightarrow{}  (\mdownarrow{}\mexists{}p,q:\mBbbR{}\^{}2.  (((d(a;b)  =  d(a;p))  \mwedge{}  (d(c;d)  =  d(c;q)))  \mwedge{}  (d(c;p)  \mleq{}  d(c;d))  \mwedge{}  (d(a;q)  \mleq{}  d(a;b))))
    {}\mRightarrow{}  (\mexists{}u,v:\{p:\mBbbR{}\^{}2|  ab=ap  \mwedge{}  cd=cp\} 
              ((\mdownarrow{}\mexists{}p,q:\mBbbR{}\^{}2
                      (((d(a;b)  =  d(a;p))  \mwedge{}  (d(c;d)  =  d(c;q)))  \mwedge{}  (d(c;p)  <  d(c;d))  \mwedge{}  (d(a;q)  <  d(a;b))))
              {}\mRightarrow{}  (r2-left(u;c;a)  \mwedge{}  r2-left(v;a;c)))))



Date html generated: 2017_10_03-AM-11_53_00
Last ObjectModification: 2017_08_13-PM-00_48_29

Theory : reals


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