Nuprl Lemma : midpoint-of-equidistant-points-is-perp

∀e:EuclideanPlane. ∀u:Point. ∀v:{v:Point| u # v} . ∀c:{c:Point| c # uv} .  (cu ≅ cv ⇒ (∀m:Point. (u=m=v ⇒ uv  ⊥m mc)))


Proof




Definitions occuring in Statement :  geo-perp-in: ab  ⊥x cd,  euclidean-plane: EuclideanPlane,  geo-midpoint: a=m=b,  geo-congruent: ab ≅ cd,  geo-lsep: a # bc,  geo-sep: a # b,  geo-point: Point,  all: ∀x:A. B[x],  implies: P ⇒ Q,  set: {x:A| B[x]} 
Definitions unfolded in proof :  rev_implies: P ⇐ Q,  subtract: n - m,  cons: [a / b],  select: L[n],  exists: ∃x:A. B[x],  satisfiable_int_formula: satisfiable_int_formula(fmla),  decidable: Dec(P),  lelt: i ≤ j < k,  int_seg: {i..j-},  top: Top,  l_all: (∀x∈L.P[x]),  geo-colinear-set: geo-colinear-set(e; L),  cand: A c∧ B,  oriented-plane: OrientedPlane,  rev_uimplies: rev_uimplies(P;Q),  uiff: uiff(P;Q),  iff: P ⇐⇒ Q,  geo-eq: a ≡ b,  stable: Stable{P},  false: False,  not: ¬A,  or: P ∨ Q,  geo-perp-in: ab  ⊥x cd,  squash: ↓T,  sq_stable: SqStable(P),  basic-geometry: BasicGeometry,  and: P ∧ Q,  geo-midpoint: a=m=b,  prop: ℙ,  uimplies: b supposing a,  guard: {T},  subtype_rel: A ⊆r B,  uall: ∀[x:A]. B[x],  member: t ∈ T,  implies: P ⇒ Q,  all: ∀x:A. B[x]
Lemmas referenced :  geo-colinear-permute,  euclidean-plane-axioms,  geo-sep-irrefl',  geo-congruence-identity,  right-angle-symmetry,  geo-length-flip,  geo-congruent-iff-length,  colinear-implies-midpoint,  implies-right-angle,  geo-sep-sym,  geo-perp-in-iff,  geo-colinear-same,  istype-less_than,  istype-le,  int_formula_prop_less_lemma,  intformless_wf,  decidable__lt,  int_formula_prop_wf,  int_term_value_constant_lemma,  int_formula_prop_le_lemma,  int_formula_prop_not_lemma,  istype-int,  itermConstant_wf,  intformle_wf,  intformnot_wf,  full-omega-unsat,  decidable__le,  length_of_nil_lemma,  length_of_cons_lemma,  geo-between-implies-colinear,  geo-colinear-is-colinear-set,  geo-sep_functionality,  geo-lsep_functionality,  minimal-not-not-excluded-middle,  geo-perp-in_functionality,  geo-between_functionality,  geo-eq_weakening,  geo-congruent_functionality,  minimal-double-negation-hyp-elim,  istype-void,  right-angle_wf,  geo-colinear_wf,  not_wf,  false_wf,  stable__geo-perp-in,  sq_stable__geo-perp-in,  geo-point_wf,  geo-sep_wf,  geo-lsep_wf,  geo-congruent_wf,  geo-primitives_wf,  euclidean-plane-structure_wf,  euclidean-plane_wf,  subtype_rel_transitivity,  euclidean-plane-subtype,  euclidean-plane-structure-subtype,  geo-midpoint_wf
Rules used in proof :  equalitySymmetry,  equalityTransitivity,  lambdaEquality_alt,  dependent_pairFormation_alt,  approximateComputation,  independent_pairFormation,  natural_numberEquality,  dependent_set_memberEquality_alt,  isect_memberEquality_alt,  promote_hyp,  voidElimination,  unionElimination,  unionIsType,  productIsType,  functionIsType,  productEquality,  functionEquality,  unionEquality,  imageElimination,  baseClosed,  imageMemberEquality,  independent_functionElimination,  dependent_functionElimination,  productElimination,  setIsType,  because_Cache,  inhabitedIsType,  rename,  setElimination,  sqequalRule,  independent_isectElimination,  instantiate,  hypothesis,  applyEquality,  hypothesisEquality,  thin,  isectElimination,  sqequalHypSubstitution,  extract_by_obid,  introduction,  cut,  universeIsType,  lambdaFormation_alt,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution

Latex:
\mforall{}e:EuclideanPlane.  \mforall{}u:Point.  \mforall{}v:\{v:Point|  u  \#  v\}  .  \mforall{}c:\{c:Point|  c  \#  uv\}  .
    (cu  \mcong{}  cv  {}\mRightarrow{}  (\mforall{}m:Point.  (u=m=v  {}\mRightarrow{}  uv    \mbot{}m  mc)))



Date html generated: 2019_10_29-AM-09_17_12
Last ObjectModification: 2019_10_18-PM-03_15_32

Theory : euclidean!plane!geometry


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