Nuprl Lemma : Euclid-Prop31

∀e:EuclideanPlane. ∀a,b,x:Point.  (a # b ⇒ x # ab ⇒ (∃y:Point. geo-parallel-points(e;a;b;x;y)))


Proof




Definitions occuring in Statement :  geo-parallel-points: geo-parallel-points(e;a;b;c;d),  euclidean-plane: EuclideanPlane,  geo-lsep: a # bc,  geo-sep: a # b,  geo-point: Point,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  subtype_rel: A ⊆r B,  prop: ℙ,  exists: ∃x:A. B[x],  sq_exists: ∃x:A [B[x]],  and: P ∧ Q,  basic-geometry: BasicGeometry,  guard: {T},  uimplies: b supposing a,  euclidean-plane: EuclideanPlane,  cand: A c∧ B,  sq_stable: SqStable(P),  squash: ↓T,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  not: ¬A,  geo-perp-in: ab  ⊥x cd,  basic-geometry-: BasicGeometry-,  l_member: (x ∈ l),  nat: ℕ,  le: A ≤ B,  less_than': less_than'(a;b),  false: False,  select: L[n],  cons: [a / b],  less_than: a < b,  true: True,  ge: i ≥ j ,  decidable: Dec(P),  or: P ∨ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  subtract: n - m,  append: as @ bs,  so_lambda: so_lambda3,  so_apply: x[s1;s2;s3],  geo-colinear-set: geo-colinear-set(e; L),  l_all: (∀x∈L.P[x]),  int_seg: {i..j-},  lelt: i ≤ j < k,  geo-eq: a ≡ b

Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,x:Point.    (a  \#  b  {}\mRightarrow{}  x  \#  ab  {}\mRightarrow{}  (\mexists{}y:Point.  geo-parallel-points(e;a;b;x;y)))



Date html generated: 2020_05_20-AM-10_43_31
Last ObjectModification: 2020_01_13-PM-10_28_13

Theory : euclidean!plane!geometry


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