Nuprl Lemma : use-plane-sep
∀g:EuclideanPlaneStructure. ∀a,b,u,v:Point.  (u leftof ab 
⇒ v leftof ba 
⇒ (∃x:Point. (Colinear(a;b;x) ∧ u_x_v)))
Proof
Definitions occuring in Statement : 
euclidean-plane-structure: EuclideanPlaneStructure
, 
geo-colinear: Colinear(a;b;c)
, 
geo-left: a leftof bc
, 
geo-between: a_b_c
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
Definitions unfolded in proof : 
squash: ↓T
, 
sq_stable: SqStable(P)
, 
exists: ∃x:A. B[x]
, 
so_apply: x[s]
, 
and: P ∧ Q
, 
so_lambda: λ2x.t[x]
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
Lemmas referenced : 
sq_stable__geo-between, 
sq_stable__colinear, 
sq_stable__and, 
euclidean-plane-structure_wf, 
equal_wf, 
geo-between_wf, 
geo-colinear_wf, 
euclidean-plane-structure-subtype, 
geo-point_wf, 
set_wf, 
geo-left_wf, 
geo-SS_wf
Rules used in proof : 
imageElimination, 
baseClosed, 
imageMemberEquality, 
productElimination, 
isect_memberEquality, 
independent_functionElimination, 
dependent_functionElimination, 
dependent_pairFormation, 
rename, 
setElimination, 
productEquality, 
lambdaEquality, 
equalitySymmetry, 
equalityTransitivity, 
sqequalRule, 
because_Cache, 
applyEquality, 
hypothesis, 
dependent_set_memberEquality, 
hypothesisEquality, 
thin, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
cut, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}g:EuclideanPlaneStructure.  \mforall{}a,b,u,v:Point.
    (u  leftof  ab  {}\mRightarrow{}  v  leftof  ba  {}\mRightarrow{}  (\mexists{}x:Point.  (Colinear(a;b;x)  \mwedge{}  u\_x\_v)))
Date html generated:
2017_10_02-PM-03_26_29
Last ObjectModification:
2017_08_13-PM-08_20_30
Theory : euclidean!plane!geometry
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