Nuprl Lemma : eu-eq_dist-axiomA9
∀e:EuclideanPlane. ∀a1,a2,a3,a4,a5,a6,b:Point.  (D(a1;a2;a3;a4;a5;a6) 
⇒ (a4 ≠ b ∨ D(a1;a2;a3;b;a5;a6)))
Proof
Definitions occuring in Statement : 
dist: D(a;b;c;d;e;f)
, 
euclidean-plane: EuclideanPlane
, 
geo-sep: a ≠ b
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
or: P ∨ Q
Definitions unfolded in proof : 
uimplies: b supposing a
, 
guard: {T}
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
or: P ∨ Q
, 
rev_implies: P 
⇐ Q
, 
and: P ∧ Q
, 
iff: P 
⇐⇒ Q
, 
euclidean-plane: EuclideanPlane
, 
uall: ∀[x:A]. B[x]
, 
basic-geometry: BasicGeometry
, 
member: t ∈ T
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
Lemmas referenced : 
geo-point_wf, 
dist_wf, 
geo-primitives_wf, 
euclidean-plane-structure_wf, 
euclidean-plane_wf, 
subtype_rel_transitivity, 
euclidean-plane-subtype, 
euclidean-plane-structure-subtype, 
geo-sep_wf, 
geo-sep-or, 
geo-length_wf, 
geo-add-length_wf, 
geo-lt_wf, 
geo-add-length_wf1, 
geo-mk-seg_wf, 
geo-length_wf1, 
geo-sep-iff-or-lt, 
dist-lemma-lt, 
dist-lemma-lt2, 
geo-add-length-cancel-left-lt, 
geo-le_weakening-lt, 
geo-lt_transitivity, 
geo-lt-lengths-to-sep, 
geo-sep-sym
Rules used in proof : 
unionElimination, 
equalitySymmetry, 
equalityTransitivity, 
independent_isectElimination, 
instantiate, 
dependent_set_memberEquality_alt, 
inhabitedIsType, 
lambdaEquality_alt, 
applyEquality, 
universeIsType, 
inlFormation_alt, 
productElimination, 
because_Cache, 
rename, 
setElimination, 
isectElimination, 
sqequalRule, 
hypothesis, 
independent_functionElimination, 
hypothesisEquality, 
thin, 
dependent_functionElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
cut, 
lambdaFormation_alt, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
inrFormation_alt
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a1,a2,a3,a4,a5,a6,b:Point.
    (D(a1;a2;a3;a4;a5;a6)  {}\mRightarrow{}  (a4  \mneq{}  b  \mvee{}  D(a1;a2;a3;b;a5;a6)))
Date html generated:
2019_10_16-PM-02_57_56
Last ObjectModification:
2019_04_22-PM-01_32_18
Theory : euclidean!plane!geometry
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