Nuprl Lemma : eu-colinear-transitivity
∀e:EuclideanPlane
  ∀[A,C,B,D:Point].  (Colinear(A;B;C) 
⇒ Colinear(B;C;D) 
⇒ {((¬(A = C ∈ Point)) 
⇒ Colinear(A;C;D)) ∧ Colinear(A;B;D)})
Proof
Definitions occuring in Statement : 
euclidean-plane: EuclideanPlane
, 
eu-colinear: Colinear(a;b;c)
, 
eu-point: Point
, 
uall: ∀[x:A]. B[x]
, 
guard: {T}
, 
all: ∀x:A. B[x]
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
uall: ∀[x:A]. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
euclidean-plane: EuclideanPlane
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
guard: {T}
, 
sq_stable: SqStable(P)
, 
not: ¬A
, 
false: False
, 
prop: ℙ
, 
uimplies: b supposing a
, 
squash: ↓T
Lemmas referenced : 
eu-colinear-def, 
sq_stable__colinear, 
eu-colinear-cases, 
eu-colinear_wf, 
stable__colinear, 
not_wf, 
equal_wf, 
eu-point_wf, 
eu-between-eq-implies-colinear2, 
eu-between-implies-between-eq, 
eu-between-eq-symmetry, 
eu-between-eq-inner-trans, 
eu-between-eq-exchange3, 
eu-between-eq-exchange4, 
eu-between-eq-outer-trans, 
eu-between_wf, 
eu-between-eq-implies-colinear, 
eu-colinear-permute, 
eu-colinear-swap, 
not-eu-between-same, 
not-eu-between-same2, 
euclidean-plane_wf, 
eu-between-eq-trivial-right, 
eu-colinear-between, 
eu-colinear-same-side, 
eu-colinear-same-side2, 
eu-between-eq_wf, 
eu-between-same2
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
isect_memberFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
setElimination, 
rename, 
because_Cache, 
hypothesis, 
isectElimination, 
hypothesisEquality, 
productElimination, 
independent_functionElimination, 
independent_pairFormation, 
equalitySymmetry, 
voidElimination, 
productEquality, 
equalityEquality, 
promote_hyp, 
hyp_replacement, 
Error :applyLambdaEquality, 
sqequalRule, 
independent_isectElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
equalityTransitivity, 
universeEquality
Latex:
\mforall{}e:EuclideanPlane
    \mforall{}[A,C,B,D:Point].
        (Colinear(A;B;C)  {}\mRightarrow{}  Colinear(B;C;D)  {}\mRightarrow{}  \{((\mneg{}(A  =  C))  {}\mRightarrow{}  Colinear(A;C;D))  \mwedge{}  Colinear(A;B;D)\})
Date html generated:
2016_10_26-AM-07_43_27
Last ObjectModification:
2016_07_12-AM-08_14_11
Theory : euclidean!geometry
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