Nuprl Lemma : eu-colinear-permute
∀e:EuclideanPlane. ∀a,b,c:Point.  ((¬(c = b ∈ Point)) ⇒ Colinear(a;b;c) ⇒ Colinear(c;b;a))
Proof
Definitions occuring in Statement : 
euclidean-plane: EuclideanPlane, 
eu-colinear: Colinear(a;b;c), 
eu-point: Point, 
all: ∀x:A. B[x], 
not: ¬A, 
implies: P ⇒ Q, 
equal: s = t ∈ T
Definitions unfolded in proof : 
prop: ℙ, 
false: False, 
cand: A c∧ B, 
not: ¬A, 
rev_implies: P ⇐ Q, 
and: P ∧ Q, 
iff: P ⇐⇒ Q, 
uall: ∀[x:A]. B[x], 
euclidean-plane: EuclideanPlane, 
member: t ∈ T, 
implies: P ⇒ Q, 
all: ∀x:A. B[x], 
uimplies: b supposing a
Lemmas referenced : 
eu-between-sym, 
eu-colinear-def, 
equal_wf, 
eu-point_wf, 
not_wf, 
eu-between_wf, 
eu-colinear_wf, 
euclidean-plane_wf
Rules used in proof : 
because_Cache, 
productEquality, 
voidElimination, 
equalitySymmetry, 
introduction, 
independent_pairFormation, 
independent_functionElimination, 
productElimination, 
hypothesis, 
isectElimination, 
hypothesisEquality, 
rename, 
setElimination, 
thin, 
dependent_functionElimination, 
sqequalHypSubstitution, 
lemma_by_obid, 
cut, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
independent_isectElimination
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c:Point.    ((\mneg{}(c  =  b))  {}\mRightarrow{}  Colinear(a;b;c)  {}\mRightarrow{}  Colinear(c;b;a))
Date html generated:
2016_05_18-AM-06_35_50
Last ObjectModification:
2016_01_01-PM-01_13_04
Theory : euclidean!geometry
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