Nuprl Lemma : eu-colinear-trivial
∀e:EuclideanPlane. ∀a,b:Point.  ((¬(a = b ∈ Point)) 
⇒ (Colinear(a;b;b) ∧ Colinear(b;a;b)))
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
, 
and: P ∧ Q
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
not: ¬A
, 
false: False
, 
member: t ∈ T
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
euclidean-plane: EuclideanPlane
, 
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
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
eu-between_wf, 
member_wf, 
eu-colinear-def, 
euclidean-plane_wf, 
not_wf, 
lelt_wf, 
false_wf, 
length_of_nil_lemma, 
length_of_cons_lemma, 
eu-colinear-is-colinear-set, 
eu-point_wf, 
equal_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
independent_pairFormation, 
hypothesis, 
sqequalHypSubstitution, 
independent_functionElimination, 
thin, 
equalitySymmetry, 
voidElimination, 
lemma_by_obid, 
isectElimination, 
setElimination, 
rename, 
hypothesisEquality, 
dependent_functionElimination, 
because_Cache, 
sqequalRule, 
isect_memberEquality, 
voidEquality, 
dependent_set_memberEquality, 
natural_numberEquality, 
introduction, 
imageMemberEquality, 
baseClosed, 
productElimination, 
productEquality
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b:Point.    ((\mneg{}(a  =  b))  {}\mRightarrow{}  (Colinear(a;b;b)  \mwedge{}  Colinear(b;a;b)))
Date html generated:
2016_05_18-AM-06_44_28
Last ObjectModification:
2016_01_16-PM-10_30_16
Theory : euclidean!geometry
Home
Index