Nuprl Lemma : geo-perp-in-unicity2
∀e:BasicGeometry. ∀a,b,c:Point.
  ((¬Colinear(a;b;c))
  
⇒ (∀d,x:Point.  (c ≠ d 
⇒ ab  ⊥x cd 
⇒ (∀y:Point. (Colinear(a;b;y) 
⇒ Colinear(c;d;y) 
⇒ x ≡ y)))))
Proof
Definitions occuring in Statement : 
geo-perp-in: ab  ⊥x cd
, 
basic-geometry: BasicGeometry
, 
geo-colinear: Colinear(a;b;c)
, 
geo-eq: a ≡ b
, 
geo-sep: a ≠ b
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
not: ¬A
, 
implies: P 
⇒ Q
Definitions unfolded in proof : 
uimplies: b supposing a
, 
guard: {T}
, 
subtype_rel: A ⊆r B
, 
basic-geometry: BasicGeometry
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
member: t ∈ T
, 
and: P ∧ Q
, 
geo-perp-in: ab  ⊥x cd
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
Lemmas referenced : 
not_wf, 
geo-sep_wf, 
geo-perp-in_wf, 
Error :basic-geo-primitives_wf, 
Error :basic-geo-structure_wf, 
basic-geometry_wf, 
subtype_rel_transitivity, 
basic-geometry-subtype, 
geo-point_wf, 
geo-colinear_wf, 
geo-intersection-unicity
Rules used in proof : 
because_Cache, 
sqequalRule, 
independent_isectElimination, 
instantiate, 
applyEquality, 
rename, 
setElimination, 
isectElimination, 
hypothesis, 
independent_functionElimination, 
hypothesisEquality, 
dependent_functionElimination, 
extract_by_obid, 
introduction, 
cut, 
thin, 
productElimination, 
sqequalHypSubstitution, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}e:BasicGeometry.  \mforall{}a,b,c:Point.
    ((\mneg{}Colinear(a;b;c))
    {}\mRightarrow{}  (\mforall{}d,x:Point.
                (c  \mneq{}  d  {}\mRightarrow{}  ab    \mbot{}x  cd  {}\mRightarrow{}  (\mforall{}y:Point.  (Colinear(a;b;y)  {}\mRightarrow{}  Colinear(c;d;y)  {}\mRightarrow{}  x  \mequiv{}  y)))))
Date html generated:
2017_10_02-PM-06_43_29
Last ObjectModification:
2017_08_05-PM-04_49_25
Theory : euclidean!plane!geometry
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