Nuprl Lemma : eu-colinear-switch2
∀e:EuclideanPlane. ∀a,b,c:Point.  (Colinear(a;b;c) ⇒ Colinear(b;a;c))
Proof
Definitions occuring in Statement : 
euclidean-plane: EuclideanPlane, 
eu-colinear: Colinear(a;b;c), 
eu-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, 
euclidean-plane: EuclideanPlane, 
uall: ∀[x:A]. B[x], 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
not: ¬A, 
false: False, 
prop: ℙ, 
eu-colinear-set: eu-colinear-set(e;L), 
l_all: (∀x∈L.P[x]), 
top: Top, 
int_seg: {i..j-}, 
lelt: i ≤ j < k, 
le: A ≤ B, 
less_than': less_than'(a;b), 
less_than: a < b, 
squash: ↓T, 
true: True, 
select: L[n], 
cons: [a / b], 
subtract: n - m
Lemmas referenced : 
euclidean-plane_wf, 
eu-colinear_wf, 
lelt_wf, 
false_wf, 
length_of_nil_lemma, 
length_of_cons_lemma, 
eu-colinear-is-colinear-set, 
eu-point_wf, 
equal_wf, 
eu-colinear-def
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
setElimination, 
rename, 
hypothesisEquality, 
isectElimination, 
hypothesis, 
productElimination, 
independent_functionElimination, 
equalitySymmetry, 
voidElimination, 
because_Cache, 
sqequalRule, 
isect_memberEquality, 
voidEquality, 
dependent_set_memberEquality, 
natural_numberEquality, 
independent_pairFormation, 
introduction, 
imageMemberEquality, 
baseClosed
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c:Point.    (Colinear(a;b;c)  {}\mRightarrow{}  Colinear(b;a;c))
Date html generated:
2016_05_18-AM-06_44_19
Last ObjectModification:
2016_01_16-PM-10_28_34
Theory : euclidean!geometry
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