Nuprl Lemma : geo-pt-swap-preserves-parallel

∀e:EuclideanPlane. ∀a,b,c,d:Point. ∀A:a ≠ b. ∀C:c ≠ d. ∀A':b ≠ a.  (<a, b, A> || <c, d, C> ⇒ <b, a, A'> || <c, d, C>)


Proof




Definitions occuring in Statement :  geo-Aparallel: l || m,  euclidean-plane: EuclideanPlane,  geo-sep: a ≠ b,  geo-point: Point,  all: ∀x:A. B[x],  implies: P ⇒ Q,  pair: <a, b>
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  squash: ↓T,  uall: ∀[x:A]. B[x],  prop: ℙ,  geo-line: Line,  subtype_rel: A ⊆r B,  true: True,  uimplies: b supposing a,  guard: {T},  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q,  geoline: LINE,  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  pi1: fst(t),  pi2: snd(t),  basic-geometry: BasicGeometry
Lemmas referenced :  geo-Aparallel_wf,  squash_wf,  true_wf,  geoline_wf,  trivial-equal,  geo-sep_wf,  geo-point_wf,  geoline-subtype1,  iff_weakening_equal,  euclidean-plane_wf,  quotient-member-eq,  geo-line_wf,  euclidean-plane-structure-subtype,  euclidean-plane-subtype,  subtype_rel_transitivity,  euclidean-plane-structure_wf,  geo-primitives_wf,  geo-line-eq_wf,  geo-line-eq-equiv,  geo-colinear-line-eq2,  geo-colinear-same
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  applyEquality,  thin,  lambdaEquality,  sqequalHypSubstitution,  imageElimination,  introduction,  extract_by_obid,  isectElimination,  hypothesisEquality,  equalityTransitivity,  hypothesis,  equalitySymmetry,  because_Cache,  sqequalRule,  dependent_pairEquality,  productEquality,  natural_numberEquality,  imageMemberEquality,  baseClosed,  independent_isectElimination,  productElimination,  independent_functionElimination,  dependent_functionElimination,  instantiate

Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c,d:Point.  \mforall{}A:a  \mneq{}  b.  \mforall{}C:c  \mneq{}  d.  \mforall{}A':b  \mneq{}  a.
    (<a,  b,  A>  ||  <c,  d,  C>  {}\mRightarrow{}  <b,  a,  A'>  ||  <c,  d,  C>)



Date html generated: 2018_05_22-PM-01_18_48
Last ObjectModification: 2018_05_11-PM-06_53_57

Theory : euclidean!plane!geometry


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