Nuprl Lemma : pgeo-plsep-implies-join
∀g:BasicProjectivePlane. ∀c:Point. ∀l:Line.  (c ≠ l 
⇒ (∀a,b:Point. ∀s:a ≠ b.  ((a I l ∧ b I l) 
⇒ c ≠ a ∨ b)))
Proof
Definitions occuring in Statement : 
basic-projective-plane: BasicProjectivePlane
, 
pgeo-join: p ∨ q
, 
pgeo-psep: a ≠ b
, 
pgeo-incident: a I b
, 
pgeo-plsep: a ≠ b
, 
pgeo-line: Line
, 
pgeo-point: Point
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
Definitions unfolded in proof : 
uimplies: b supposing a
, 
guard: {T}
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
member: t ∈ T
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
, 
or: P ∨ Q
, 
basic-projective-plane: BasicProjectivePlane
, 
false: False
, 
not: ¬A
, 
pgeo-leq: a ≡ b
Lemmas referenced : 
pgeo-line_wf, 
pgeo-plsep_wf, 
pgeo-point_wf, 
pgeo-psep_wf, 
pgeo-primitives_wf, 
projective-plane-structure_wf, 
basic-projective-plane_wf, 
subtype_rel_transitivity, 
basic-projective-plane-subtype, 
projective-plane-structure_subtype, 
pgeo-incident_wf, 
pgeo-join_wf, 
PL-sep-or, 
pgeo-join-to-line
Rules used in proof : 
because_Cache, 
sqequalRule, 
independent_isectElimination, 
instantiate, 
hypothesis, 
applyEquality, 
hypothesisEquality, 
isectElimination, 
extract_by_obid, 
introduction, 
cut, 
productEquality, 
thin, 
productElimination, 
sqequalHypSubstitution, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
unionElimination, 
independent_functionElimination, 
setEquality, 
lambdaEquality, 
rename, 
setElimination, 
dependent_functionElimination, 
voidElimination
Latex:
\mforall{}g:BasicProjectivePlane.  \mforall{}c:Point.  \mforall{}l:Line.
    (c  \mneq{}  l  {}\mRightarrow{}  (\mforall{}a,b:Point.  \mforall{}s:a  \mneq{}  b.    ((a  I  l  \mwedge{}  b  I  l)  {}\mRightarrow{}  c  \mneq{}  a  \mvee{}  b)))
Date html generated:
2018_05_22-PM-00_36_08
Last ObjectModification:
2017_11_15-PM-00_54_43
Theory : euclidean!plane!geometry
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