Nuprl Lemma : no-three-colinear-on-circle
∀[e:EuclideanPlane]. ∀[a:Point]. ∀[b:{b:Point| b ≠ a} ]. ∀[c:{c:Point| c ≠ a ∧ c ≠ b ∧ Colinear(a;b;c)} ].
  ∀p:Point. (¬(pa ≅ pb ∧ pb ≅ pc))
Proof
Definitions occuring in Statement : 
euclidean-plane: EuclideanPlane
, 
geo-colinear: Colinear(a;b;c)
, 
geo-congruent: ab ≅ cd
, 
geo-sep: a ≠ b
, 
geo-point: Point
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
not: ¬A
, 
and: P ∧ Q
, 
set: {x:A| B[x]} 
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
false: False
, 
and: P ∧ Q
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
uimplies: b supposing a
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
stable: Stable{P}
, 
or: P ∨ Q
, 
sq_exists: ∃x:A [B[x]]
, 
cand: A c∧ B
, 
geo-colinear-set: geo-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
, 
geo-eq: a ≡ b
, 
oriented-plane: OrientedPlane
, 
exists: ∃x:A. B[x]
, 
geo-midpoint: a=m=b
, 
append: as @ bs
, 
so_lambda: so_lambda(x,y,z.t[x; y; z])
, 
so_apply: x[s1;s2;s3]
, 
basic-geometry: BasicGeometry
, 
geo-perp: ab ⊥ cd
Lemmas referenced : 
geo-congruent_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geo-point_wf, 
set_wf, 
geo-sep_wf, 
geo-colinear_wf, 
stable__false, 
false_wf, 
or_wf, 
geo-lsep_wf, 
not_wf, 
minimal-double-negation-hyp-elim, 
minimal-not-not-excluded-middle, 
Euclid-midpoint, 
geo-sep-sym, 
midpoint-of-equidistant-points-is-perp, 
colinear-lsep-cycle, 
lsep-all-sym, 
geo-colinear-is-colinear-set, 
length_of_cons_lemma, 
length_of_nil_lemma, 
lelt_wf, 
not-lsep-iff-colinear, 
oriented-colinear-append, 
cons_wf, 
nil_wf, 
cons_member, 
l_member_wf, 
equal_wf, 
exists_wf, 
geo-between-implies-colinear, 
list_ind_cons_lemma, 
list_ind_nil_lemma, 
geo-colinear_functionality, 
geo-eq_weakening, 
geo-perp-unicity, 
geo-perp-in_wf, 
geo-perp-symmetry, 
geo-perp-symmetry2, 
geo-perp-colinear, 
geo-between_wf, 
geo-between_functionality, 
geo-eq_inversion, 
geo-congruent_functionality, 
seg-midpoints-equal-flip, 
colinear-implies-midpoint
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
lambdaFormation, 
thin, 
setElimination, 
rename, 
sqequalHypSubstitution, 
productElimination, 
hypothesis, 
because_Cache, 
independent_functionElimination, 
voidElimination, 
productEquality, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
applyEquality, 
instantiate, 
independent_isectElimination, 
sqequalRule, 
lambdaEquality, 
dependent_functionElimination, 
isect_memberEquality, 
functionEquality, 
unionElimination, 
dependent_set_memberEquality, 
voidEquality, 
natural_numberEquality, 
independent_pairFormation, 
imageMemberEquality, 
baseClosed, 
addLevel, 
impliesFunctionality, 
dependent_pairFormation, 
inrFormation, 
inlFormation
Latex:
\mforall{}[e:EuclideanPlane].  \mforall{}[a:Point].  \mforall{}[b:\{b:Point|  b  \mneq{}  a\}  ].  \mforall{}[c:\{c:Point| 
                                                                                                                          c  \mneq{}  a  \mwedge{}  c  \mneq{}  b  \mwedge{}  Colinear(a;b;c)\}  ].
    \mforall{}p:Point.  (\mneg{}(pa  \mcong{}  pb  \mwedge{}  pb  \mcong{}  pc))
Date html generated:
2018_05_22-PM-00_10_20
Last ObjectModification:
2018_05_11-PM-06_48_20
Theory : euclidean!plane!geometry
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