Nuprl Lemma : plsep-join-implies
∀g:ProjectivePlane. ∀p,q,r:Point. ∀s:p ≠ q.  (r ≠ p ∨ q 
⇒ {q ≠ r ∧ p ≠ r})
Proof
Definitions occuring in Statement : 
projective-plane: ProjectivePlane
, 
pgeo-join: p ∨ q
, 
pgeo-psep: a ≠ b
, 
pgeo-plsep: a ≠ b
, 
pgeo-point: Point
, 
guard: {T}
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
Definitions unfolded in proof : 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
guard: {T}
, 
subtype_rel: A ⊆r B
, 
and: P ∧ Q
, 
exists: ∃x:A. B[x]
, 
member: t ∈ T
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
, 
cand: A c∧ B
, 
pgeo-psep: a ≠ b
, 
false: False
, 
not: ¬A
, 
pgeo-leq: a ≡ b
, 
or: P ∨ Q
Lemmas referenced : 
pgeo-point_wf, 
pgeo-psep_wf, 
pgeo-incident_wf, 
pgeo-line_wf, 
pgeo-join_wf, 
pgeo-primitives_wf, 
projective-plane-structure_wf, 
projective-plane-structure-complete_wf, 
projective-plane_wf, 
subtype_rel_transitivity, 
projective-plane-subtype, 
projective-plane-structure-complete_subtype, 
projective-plane-structure_subtype, 
pgeo-plsep_wf, 
projective-plane-subtype-basic, 
pgeo-join-to-line-2, 
Join, 
PL-sep-or
Rules used in proof : 
productEquality, 
setEquality, 
rename, 
setElimination, 
lambdaEquality, 
independent_isectElimination, 
instantiate, 
isectElimination, 
independent_pairFormation, 
sqequalRule, 
applyEquality, 
productElimination, 
hypothesis, 
independent_functionElimination, 
hypothesisEquality, 
because_Cache, 
thin, 
dependent_functionElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
cut, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
dependent_pairFormation, 
voidElimination, 
unionElimination
Latex:
\mforall{}g:ProjectivePlane.  \mforall{}p,q,r:Point.  \mforall{}s:p  \mneq{}  q.    (r  \mneq{}  p  \mvee{}  q  {}\mRightarrow{}  \{q  \mneq{}  r  \mwedge{}  p  \mneq{}  r\})
Date html generated:
2018_05_22-PM-00_41_54
Last ObjectModification:
2017_11_28-PM-04_20_49
Theory : euclidean!plane!geometry
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