Nuprl Lemma : pgeo-join-to-line
∀g:BasicProjectivePlane. ∀p,q:Point. ∀l:Line. ∀s:p ≠ q.  (p I l ⇒ q I l ⇒ p ∨ q ≡ l)
Proof
Definitions occuring in Statement : 
basic-projective-plane: BasicProjectivePlane, 
pgeo-join: p ∨ q, 
pgeo-leq: a ≡ b, 
pgeo-psep: a ≠ b, 
pgeo-incident: a I b, 
pgeo-line: Line, 
pgeo-point: Point, 
all: ∀x:A. B[x], 
implies: P ⇒ Q
Definitions unfolded in proof : 
pgeo-peq: a ≡ b, 
guard: {T}, 
false: False, 
cand: A c∧ B, 
uimplies: b supposing a, 
prop: ℙ, 
and: P ∧ Q, 
subtype_rel: A ⊆r B, 
basic-projective-plane: BasicProjectivePlane, 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
not: ¬A, 
pgeo-leq: a ≡ b, 
implies: P ⇒ Q, 
all: ∀x:A. B[x]
Lemmas referenced : 
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-lsep_wf, 
pgeo-leq_wf, 
pgeo-peq_wf, 
incident-join-second, 
incident-join-first, 
pgeo-incident_wf, 
pgeo-line_wf, 
pgeo-join_wf, 
Unique
Rules used in proof : 
instantiate, 
voidElimination, 
independent_functionElimination, 
independent_pairFormation, 
independent_isectElimination, 
productEquality, 
sqequalRule, 
setEquality, 
lambdaEquality, 
applyEquality, 
hypothesis, 
because_Cache, 
rename, 
setElimination, 
isectElimination, 
hypothesisEquality, 
thin, 
dependent_functionElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
cut, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}g:BasicProjectivePlane.  \mforall{}p,q:Point.  \mforall{}l:Line.  \mforall{}s:p  \mneq{}  q.    (p  I  l  {}\mRightarrow{}  q  I  l  {}\mRightarrow{}  p  \mvee{}  q  \mequiv{}  l)
Date html generated:
2018_05_22-PM-00_35_39
Last ObjectModification:
2017_11_25-AM-09_05_06
Theory : euclidean!plane!geometry
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