Nuprl Lemma : geo-between-same-side2-or-strong
∀e:BasicGeometry. ∀A,B,C,d:Point.  ((A ≠ B ∧ C ≠ d) ⇒ A_B_C ⇒ A_B_d ⇒ (B_C_d ∨ B_d_C))
Proof
Definitions occuring in Statement : 
basic-geometry: BasicGeometry, 
geo-between: a_b_c, 
geo-sep: a ≠ b, 
geo-point: Point, 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
or: P ∨ Q, 
and: P ∧ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
member: t ∈ T, 
and: P ∧ Q, 
uall: ∀[x:A]. B[x], 
subtype_rel: A ⊆r B, 
guard: {T}, 
uimplies: b supposing a, 
prop: ℙ, 
or: P ∨ Q, 
basic-geometry: BasicGeometry, 
euclidean-plane: EuclideanPlane, 
basic-geometry-: BasicGeometry-
Lemmas referenced : 
geo-between-same-side-or, 
geo-between_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, 
geo-sep_wf, 
geo-point_wf, 
geo-between-symmetry, 
geo-between-inner-trans, 
geo-between-exchange3, 
subtype_rel_self, 
basic-geometry-_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
independent_functionElimination, 
hypothesis, 
productElimination, 
universeIsType, 
isectElimination, 
applyEquality, 
instantiate, 
independent_isectElimination, 
sqequalRule, 
because_Cache, 
productIsType, 
inhabitedIsType, 
unionElimination, 
inlFormation_alt, 
inrFormation_alt
Latex:
\mforall{}e:BasicGeometry.  \mforall{}A,B,C,d:Point.    ((A  \mneq{}  B  \mwedge{}  C  \mneq{}  d)  {}\mRightarrow{}  A\_B\_C  {}\mRightarrow{}  A\_B\_d  {}\mRightarrow{}  (B\_C\_d  \mvee{}  B\_d\_C))
Date html generated:
2019_10_16-PM-01_18_13
Last ObjectModification:
2019_07_24-PM-09_31_18
Theory : euclidean!plane!geometry
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