Nuprl Lemma : Euclid-prop14
∀g:EuclideanPlane. ∀a,b,x,y:Point.  (a ≠ b 
⇒ x leftof ab 
⇒ y leftof ba 
⇒ Rxba 
⇒ Ryba 
⇒ Colinear(x;b;y))
Proof
Definitions occuring in Statement : 
euclidean-plane: EuclideanPlane
, 
right-angle: Rabc
, 
geo-colinear: Colinear(a;b;c)
, 
geo-left: a leftof bc
, 
geo-sep: a ≠ b
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
basic-geometry: BasicGeometry
, 
uall: ∀[x:A]. B[x]
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
uimplies: b supposing a
, 
prop: ℙ
Lemmas referenced : 
adjacent-right-angles, 
geo-sep-sym, 
right-angle_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geo-left_wf, 
geo-sep_wf, 
geo-point_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
sqequalRule, 
hypothesisEquality, 
independent_functionElimination, 
because_Cache, 
hypothesis, 
universeIsType, 
isectElimination, 
applyEquality, 
instantiate, 
independent_isectElimination, 
inhabitedIsType
Latex:
\mforall{}g:EuclideanPlane.  \mforall{}a,b,x,y:Point.
    (a  \mneq{}  b  {}\mRightarrow{}  x  leftof  ab  {}\mRightarrow{}  y  leftof  ba  {}\mRightarrow{}  Rxba  {}\mRightarrow{}  Ryba  {}\mRightarrow{}  Colinear(x;b;y))
Date html generated:
2019_10_16-PM-01_55_51
Last ObjectModification:
2018_10_15-PM-00_32_06
Theory : euclidean!plane!geometry
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