Nuprl Lemma : euclid-Prop3
∀e:EuclideanPlane. ∀A:Point. ∀B:{B:Point| A ≠ B} . ∀C1:Point. ∀C2:{C2:Point| C1 ≠ C2} .
  (|C1C2| < |AB| 
⇒ (∃E:{Point| (A_E_B ∧ AE ≅ C1C2)}))
Proof
Definitions occuring in Statement : 
geo-lt: p < q
, 
geo-length: |s|
, 
geo-mk-seg: ab
, 
euclidean-plane: EuclideanPlane
, 
geo-congruent: ab ≅ cd
, 
geo-between: a_b_c
, 
geo-sep: a ≠ b
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
sq_exists: ∃x:{A| B[x]}
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
set: {x:A| B[x]} 
Definitions unfolded in proof : 
squash: ↓T
, 
sq_stable: SqStable(P)
, 
cand: A c∧ B
, 
and: P ∧ Q
, 
so_apply: x[s]
, 
so_lambda: λ2x.t[x]
, 
uimplies: b supposing a
, 
guard: {T}
, 
subtype_rel: A ⊆r B
, 
euclidean-plane: EuclideanPlane
, 
basic-geometry: BasicGeometry
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
member: t ∈ T
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
basic-geometry-: BasicGeometry-
, 
sq_exists: ∃x:{A| B[x]}
, 
false: False
, 
not: ¬A
, 
stable: Stable{P}
, 
uiff: uiff(P;Q)
, 
rev_implies: P 
⇐ Q
, 
iff: P 
⇐⇒ Q
, 
true: True
Lemmas referenced : 
sq_stable__geo-sep, 
sq_stable__and, 
geo-sep_wf, 
geo-primitives_wf, 
euclidean-plane-structure_wf, 
euclidean-plane_wf, 
subtype_rel_transitivity, 
euclidean-plane-subtype, 
euclidean-plane-structure-subtype, 
geo-point_wf, 
set_wf, 
geo-mk-seg_wf, 
geo-length_wf, 
geo-lt_wf, 
geo-sep-sym, 
geo-extend-exists, 
geo-congruent-sep, 
geo-congruent_wf, 
geo-between_wf, 
geo-between-symmetry, 
geo-between-same-side2, 
not_wf, 
stable__geo-between, 
geo-add-length-between, 
geo-add-length_wf, 
geo-length-type_wf, 
equal_wf, 
geo-congruent-iff-length, 
iff_weakening_equal, 
basic-geometry_wf, 
true_wf, 
squash_wf, 
geo-lt_transitivity, 
geo-le-add1, 
geo-lt-irrefl
Rules used in proof : 
imageElimination, 
baseClosed, 
imageMemberEquality, 
dependent_functionElimination, 
independent_functionElimination, 
independent_pairFormation, 
isect_memberEquality, 
lambdaEquality, 
independent_isectElimination, 
instantiate, 
applyEquality, 
because_Cache, 
hypothesis, 
hypothesisEquality, 
sqequalRule, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
rename, 
thin, 
setElimination, 
cut, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
productElimination, 
productEquality, 
dependent_set_memberFormation, 
voidElimination, 
applyLambdaEquality, 
hyp_replacement, 
equalitySymmetry, 
universeEquality, 
natural_numberEquality, 
equalityTransitivity
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}A:Point.  \mforall{}B:\{B:Point|  A  \mneq{}  B\}  .  \mforall{}C1:Point.  \mforall{}C2:\{C2:Point|  C1  \mneq{}  C2\}  .
    (|C1C2|  <  |AB|  {}\mRightarrow{}  (\mexists{}E:\{Point|  (A\_E\_B  \mwedge{}  AE  \00D0  C1C2)\}))
Date html generated:
2017_10_02-PM-06_56_07
Last ObjectModification:
2017_08_06-PM-08_41_36
Theory : euclidean!plane!geometry
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