Nuprl Lemma : center-on-circle-overlap
∀e:EuclideanPlane. ∀a,b,c:Point.  (a ≠ b 
⇒ |bc| ≤ |ab| + |ab| 
⇒ Overlap(a;b;b;c))
Proof
Definitions occuring in Statement : 
geo-add-length: p + q
, 
geo-le: p ≤ q
, 
geo-length: |s|
, 
geo-mk-seg: ab
, 
euclidean-plane: EuclideanPlane
, 
circle-overlap: Overlap(a;b;c;d)
, 
geo-sep: a ≠ b
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
circle-overlap: Overlap(a;b;c;d)
, 
exists: ∃x:A. B[x]
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
euclidean-plane: EuclideanPlane
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
guard: {T}
, 
uimplies: b supposing a
, 
uiff: uiff(P;Q)
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
squash: ↓T
, 
basic-geometry: BasicGeometry
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
geo-ge: cd ≥ ab
, 
stable: Stable{P}
, 
not: ¬A
, 
or: P ∨ Q
, 
false: False
, 
geo-eq: a ≡ b
, 
basic-geometry-: BasicGeometry-
, 
true: True
Lemmas referenced : 
geo-SCS_wf, 
geo-sep-sym, 
geo-between-trivial2, 
geo-sep_wf, 
geo-between_wf, 
geo-point_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geo-congruent_wf, 
geo-SCO_wf, 
geo-colinear_wf, 
geo-congruent-refl, 
geo-ge-trivial2, 
geo-congruent-iff-length, 
geo-SCS-congruent, 
geo-ge_wf, 
exists_wf, 
geo-le_wf, 
geo-length_wf, 
geo-mk-seg_wf, 
geo-add-length_wf, 
stable__not, 
not_wf, 
false_wf, 
or_wf, 
geo-sep_functionality, 
geo-eq_weakening, 
minimal-double-negation-hyp-elim, 
geo-congruent_functionality, 
geo-ge_functionality, 
minimal-not-not-excluded-middle, 
geo-SCS-out, 
equal_wf, 
geo-out_wf, 
set_wf, 
geo-out-iff-colinear, 
geo-between-symmetry, 
geo-between-implies-ge, 
stable__geo-ge, 
geo-simple-colinear-cases, 
geo-add-length-between, 
iff_weakening_equal, 
geo-length-type_wf, 
true_wf, 
squash_wf, 
geo-length-flip, 
basic-geometry_wf, 
geo-add-length-comm, 
geo-add-length-cancel-left-le, 
geo-le-iff, 
geo-ge-trivial, 
geo-congruence-identity
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
dependent_pairFormation, 
hypothesisEquality, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
setElimination, 
rename, 
because_Cache, 
hypothesis, 
dependent_functionElimination, 
independent_functionElimination, 
independent_pairFormation, 
dependent_set_memberEquality, 
productEquality, 
applyEquality, 
sqequalRule, 
equalityTransitivity, 
equalitySymmetry, 
lambdaEquality, 
setEquality, 
instantiate, 
independent_isectElimination, 
functionEquality, 
productElimination, 
imageMemberEquality, 
baseClosed, 
unionElimination, 
voidElimination, 
natural_numberEquality, 
universeEquality, 
imageElimination, 
promote_hyp
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c:Point.    (a  \mneq{}  b  {}\mRightarrow{}  |bc|  \mleq{}  |ab|  +  |ab|  {}\mRightarrow{}  Overlap(a;b;b;c))
Date html generated:
2018_05_22-PM-00_00_35
Last ObjectModification:
2018_03_30-AM-10_52_27
Theory : euclidean!plane!geometry
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