Nuprl Lemma : lsep-implies-sep-or-lsep

∀e:EuclideanPlane. ∀a,b,c,x:Point.  (a # bc ⇒ (c ≠ x ∨ x # ab))


Proof




Definitions occuring in Statement :  euclidean-plane: EuclideanPlane,  geo-lsep: a # bc,  geo-sep: a ≠ b,  geo-point: Point,  all: ∀x:A. B[x],  implies: P ⇒ Q,  or: P ∨ Q
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  oriented-plane: OrientedPlane,  geo-colinear-set: geo-colinear-set(e; L),  l_all: (∀x∈L.P[x]),  top: Top,  int_seg: {i..j-},  lelt: i ≤ j < k,  and: P ∧ Q,  decidable: Dec(P),  or: P ∨ Q,  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  not: ¬A,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  prop: ℙ,  false: False,  select: L[n],  cons: [a / b],  subtract: n - m,  subtype_rel: A ⊆r B,  guard: {T},  sq_exists: ∃x:A [B[x]],  euclidean-plane: EuclideanPlane,  sq_stable: SqStable(P),  squash: ↓T,  basic-geometry: BasicGeometry,  geo-equilateral: EQΔ(a;b;c),  geo-midpoint: a=m=b,  uiff: uiff(P;Q),  cand: A c∧ B,  l_member: (x ∈ l),  nat: ℕ,  le: A ≤ B,  less_than': less_than'(a;b),  less_than: a < b,  true: True,  ge: i ≥ j ,  append: as @ bs,  so_lambda: so_lambda(x,y,z.t[x; y; z]),  so_apply: x[s1;s2;s3],  iff: P ⇐⇒ Q
Lemmas referenced :  lsep-colinear-sep1,  geo-colinear-is-colinear-set,  length_of_cons_lemma,  istype-void,  length_of_nil_lemma,  decidable__le,  full-omega-unsat,  intformnot_wf,  intformle_wf,  itermConstant_wf,  istype-int,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_formula_prop_wf,  decidable__lt,  intformless_wf,  int_formula_prop_less_lemma,  istype-le,  istype-less_than,  geo-colinear_wf,  lsep-symmetry,  euclidean-plane-axioms,  colinear-equidistant-points-exist,  geo-sep-sym,  lsep-implies-sep,  geo-sep_wf,  geo-lsep_wf,  euclidean-plane-structure-subtype,  euclidean-plane-subtype,  subtype_rel_transitivity,  euclidean-plane_wf,  euclidean-plane-structure_wf,  geo-primitives_wf,  geo-point_wf,  Euclid-midpoint,  sq_stable__midpoint,  midpoint-sep,  Euclid-Prop1,  upper-dimension-axiom,  geo-congruent-iff-length,  geo-length-flip,  colinear-lsep-cycle,  lsep-all-sym,  geo-between-implies-colinear,  geo-colinear-permute,  geo-colinear-append,  cons_wf,  nil_wf,  length_wf,  select_wf,  nat_properties,  intformand_wf,  itermVar_wf,  int_formula_prop_and_lemma,  int_term_value_var_lemma,  l_member_wf,  list_ind_cons_lemma,  list_ind_nil_lemma,  geo-sep-or,  colinear-lsep,  colinear-lsep',  lsep-symmetry2,  geo-colinear-cycle,  or_comm
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  sqequalRule,  hypothesisEquality,  independent_functionElimination,  hypothesis,  isect_memberEquality_alt,  voidElimination,  dependent_set_memberEquality_alt,  natural_numberEquality,  independent_pairFormation,  unionElimination,  isectElimination,  independent_isectElimination,  approximateComputation,  dependent_pairFormation_alt,  lambdaEquality_alt,  universeIsType,  productIsType,  applyEquality,  because_Cache,  productElimination,  instantiate,  inhabitedIsType,  setElimination,  rename,  imageMemberEquality,  baseClosed,  imageElimination,  equalityTransitivity,  equalitySymmetry,  equalityIstype,  int_eqEquality,  inlFormation_alt,  inrFormation_alt

Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c,x:Point.    (a  \#  bc  {}\mRightarrow{}  (c  \mneq{}  x  \mvee{}  x  \#  ab))



Date html generated: 2019_10_16-PM-02_33_30
Last ObjectModification: 2019_07_23-PM-10_01_49

Theory : euclidean!plane!geometry


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