Nuprl Lemma : geo-inner-pasch-ex
∀e:HeytingGeometry. ∀a,b:Point. ∀c:{c:Point| c # ab} . ∀p,q:Point.  (a-p-c 
⇒ b-q-c 
⇒ (∃x:Point. (b-x-p ∧ a-x-q)))
Proof
Definitions occuring in Statement : 
geo-triangle: a # bc
, 
heyting-geometry: HeytingGeometry
, 
geo-strict-between: a-b-c
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
set: {x:A| B[x]} 
Definitions unfolded in proof : 
geo-triangle: a # bc
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
uimplies: b supposing a
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
heyting-geometry: HeytingGeometry
, 
euclidean-plane: EuclideanPlane
, 
oriented-plane: OrientedPlane
, 
and: P ∧ Q
, 
sq_exists: ∃x:{A| B[x]}
, 
exists: ∃x:A. B[x]
, 
cand: A c∧ B
, 
sq_stable: SqStable(P)
, 
squash: ↓T
Lemmas referenced : 
geo-strict-between_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
heyting-geometry-subtype, 
subtype_rel_transitivity, 
heyting-geometry_wf, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geo-point_wf, 
set_wf, 
geo-lsep_wf, 
lsep-inner-pasch-strict, 
subtype_rel_self, 
basic-geo-axioms_wf, 
geo-left-axioms_wf, 
sq_stable__and, 
sq_stable__geo-strict-between
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
applyEquality, 
hypothesis, 
instantiate, 
independent_isectElimination, 
setElimination, 
rename, 
because_Cache, 
lambdaEquality, 
dependent_functionElimination, 
setEquality, 
productEquality, 
cumulativity, 
dependent_set_memberEquality, 
dependent_pairFormation, 
productElimination, 
isect_memberEquality, 
independent_functionElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination
Latex:
\mforall{}e:HeytingGeometry.  \mforall{}a,b:Point.  \mforall{}c:\{c:Point|  c  \#  ab\}  .  \mforall{}p,q:Point.
    (a-p-c  {}\mRightarrow{}  b-q-c  {}\mRightarrow{}  (\mexists{}x:Point.  (b-x-p  \mwedge{}  a-x-q)))
Date html generated:
2017_10_02-PM-07_02_46
Last ObjectModification:
2017_08_14-PM-03_59_44
Theory : euclidean!plane!geometry
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