Nuprl Lemma : r2-straightedge-compass

∀c,d,a:ℝ^2. ∀b:{b:ℝ^2| b ≠ a ∧ c_b_d} .
  ∃u:{u:ℝ^2| cu=cd ∧ a_b_u} 
   (∃v:ℝ^2 [(cv=cd ∧ v_b_u ∧ (¬((¬a_b_v) ∧ (¬b_v_a) ∧ (¬v_a_b))) ∧ (b ≠ d ⇒ (v ≠ u ∧ u ≠ b ∧ v ≠ b)))])


Proof




Definitions occuring in Statement :  rv-be: a_b_c,  real-vec-sep: a ≠ b,  rv-congruent: ab=cd,  real-vec: ℝ^n,  all: ∀x:A. B[x],  sq_exists: ∃x:A [B[x]],  exists: ∃x:A. B[x],  not: ¬A,  implies: P ⇒ Q,  and: P ∧ Q,  set: {x:A| B[x]} ,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  member: t ∈ T,  prop: ℙ,  uall: ∀[x:A]. B[x],  nat: ℕ,  le: A ≤ B,  and: P ∧ Q,  less_than': less_than'(a;b),  false: False,  not: ¬A,  implies: P ⇒ Q,  so_lambda: λ2x.t[x],  so_apply: x[s],  sq_stable: SqStable(P),  squash: ↓T,  exists: ∃x:A. B[x],  real-vec: ℝ^n,  int_seg: {i..j-},  subtype_rel: A ⊆r B,  real-vec-dist: d(x;y),  real-vec-norm: ||x||,  real-vec-sub: X - Y,  nat_plus: ℕ+,  less_than: a < b,  true: True,  real: ℝ,  eq_int: (i =z j),  ifthenelse: if b then t else f fi ,  btrue: tt,  bfalse: ff,  uiff: uiff(P;Q),  uimplies: b supposing a,  rev_uimplies: rev_uimplies(P;Q),  req_int_terms: t1 ≡ t2,  top: Top,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  cand: A c∧ B,  real-vec-sep: a ≠ b,  rge: x ≥ y,  guard: {T},  rv-congruent: ab=cd,  rv-be: a_b_c,  rv-between: a-b-c,  sq_exists: ∃x:A [B[x]]
Lemmas referenced :  set_wf,  real-vec_wf,  false_wf,  le_wf,  real-vec-sep_wf,  rv-be_wf,  sq_stable__real-vec-sep,  real_wf,  ifthenelse_wf,  eq_int_wf,  radd_wf,  rabs_wf,  int-to-real_wf,  int_seg_wf,  req_wf,  real-vec-dist_wf,  exists_wf,  rleq_wf,  dot-product_wf,  real-vec-sub_wf,  rmul_wf,  real-regular,  rsub_wf,  less_than_wf,  regular-int-seq_wf,  itermSubtract_wf,  itermAdd_wf,  itermMultiply_wf,  itermVar_wf,  itermConstant_wf,  req-iff-rsub-is-0,  req_functionality,  r2-dot-product,  req_weakening,  real_polynomial_null,  real_term_value_sub_lemma,  real_term_value_add_lemma,  real_term_value_mul_lemma,  real_term_value_var_lemma,  real_term_value_const_lemma,  rsqrt_wf,  dot-product-nonneg,  square-nonneg,  rsqrt-of-square,  radd-non-neg,  zero-rleq-rabs,  rleq-int,  rsqrt_functionality,  rv-extend,  real-vec-between_wf,  rless_wf,  rless_functionality,  trivial-rless-radd,  rless-int,  rless_functionality_wrt_implies,  rleq_weakening_equal,  radd_functionality_wrt_rleq,  sq_stable__rless,  real-vec-dist-between,  req_transitivity,  radd_functionality,  real-vec-dist-nonneg,  rabs-bounds,  radd-preserves-rless,  rminus_wf,  radd-rminus-both,  itermMinus_wf,  real_term_value_minus_lemma,  rv-be-symmetry,  not_wf,  rv-between_wf,  rless_transitivity2,  real-vec-triangle-inequality,  rless_transitivity1,  real-vec-dist-symmetry,  rless-implies-rless,  rv-line-circle-3-ext,  sq_stable__rv-be,  rv-be-inner-trans,  req_inversion,  rv-congruent_wf,  sq_exists_wf,  rv-pos-angle_wf,  rv-be-dist,  rv-pos-angle-shift,  rv-pos-angle-permute,  rv-pos-angle-not-be,  rv-pos-angle-symmetry,  not-rv-pos-angle-implies2,  rv-T-iff,  rv-T_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  dependent_set_memberEquality,  natural_numberEquality,  sqequalRule,  independent_pairFormation,  hypothesis,  hypothesisEquality,  lambdaEquality,  productEquality,  because_Cache,  setElimination,  rename,  dependent_functionElimination,  productElimination,  independent_functionElimination,  imageMemberEquality,  baseClosed,  imageElimination,  dependent_pairFormation,  applyEquality,  setEquality,  independent_isectElimination,  approximateComputation,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  equalityTransitivity,  equalitySymmetry,  functionEquality,  impliesFunctionality,  promote_hyp

Latex:
\mforall{}c,d,a:\mBbbR{}\^{}2.  \mforall{}b:\{b:\mBbbR{}\^{}2|  b  \mneq{}  a  \mwedge{}  c\_b\_d\}  .
    \mexists{}u:\{u:\mBbbR{}\^{}2|  cu=cd  \mwedge{}  a\_b\_u\} 
      (\mexists{}v:\mBbbR{}\^{}2  [(cv=cd
                      \mwedge{}  v\_b\_u
                      \mwedge{}  (\mneg{}((\mneg{}a\_b\_v)  \mwedge{}  (\mneg{}b\_v\_a)  \mwedge{}  (\mneg{}v\_a\_b)))
                      \mwedge{}  (b  \mneq{}  d  {}\mRightarrow{}  (v  \mneq{}  u  \mwedge{}  u  \mneq{}  b  \mwedge{}  v  \mneq{}  b)))])



Date html generated: 2018_05_22-PM-02_36_58
Last ObjectModification: 2018_05_18-AM-09_46_36

Theory : reals


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