Nuprl Lemma : geo-add-length-lt-sep2
∀e:BasicGeometry. ∀a,b,c,d,g,h:Point.  (|ab| < |cd| + |gh| 
⇒ |ab| ≠ |cd| + |gh|)
Proof
Definitions occuring in Statement : 
geo-lt: p < q
, 
geo-add-length: p + q
, 
geo-length: |s|
, 
geo-mk-seg: ab
, 
basic-geometry: BasicGeometry
, 
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
, 
member: t ∈ T
, 
basic-geometry: BasicGeometry
, 
uall: ∀[x:A]. B[x]
, 
euclidean-plane: EuclideanPlane
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
uimplies: b supposing a
Lemmas referenced : 
geo-lt-iff-strict-between-points, 
geo-length_wf1, 
geo-mk-seg_wf, 
geo-add-length_wf1, 
geo-lt_wf, 
geo-length_wf, 
geo-add-length_wf, 
geo-point_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
basic-geometry-subtype, 
subtype_rel_transitivity, 
basic-geometry_wf, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
isectElimination, 
setElimination, 
rename, 
because_Cache, 
hypothesis, 
productElimination, 
independent_functionElimination, 
universeIsType, 
inhabitedIsType, 
applyEquality, 
instantiate, 
independent_isectElimination, 
sqequalRule
Latex:
\mforall{}e:BasicGeometry.  \mforall{}a,b,c,d,g,h:Point.    (|ab|  <  |cd|  +  |gh|  {}\mRightarrow{}  |ab|  \mneq{}  |cd|  +  |gh|)
Date html generated:
2019_10_16-PM-01_38_45
Last ObjectModification:
2019_02_27-PM-03_44_55
Theory : euclidean!plane!geometry
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