Nuprl Lemma : pgeo-join-to-line_dual
∀g:BasicProjectivePlane. ∀p,q:Line. ∀l:Point. ∀s:p ≠ q.  (l I p ⇒ l I q ⇒ p ∧ q ≡ l)
Proof
Definitions occuring in Statement : 
basic-projective-plane: BasicProjectivePlane, 
pgeo-meet: l ∧ m, 
pgeo-peq: a ≡ b, 
pgeo-lsep: l ≠ m, 
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, 
pgeo-meet: l ∧ m, 
mk-pgeo-prim: mk-pgeo-prim, 
btrue: tt, 
bfalse: ff, 
ifthenelse: if b then t else f fi , 
eq_atom: x =a y, 
top: Top, 
pgeo-plsep: a ≠ b, 
pgeo-lsep: l ≠ m, 
mk-pgeo: mk-pgeo(p; ss; por; lor; j; m; p3; l3), 
pgeo-dual-prim: pg*, 
pgeo-point: Point, 
pgeo-line: Line, 
pgeo-psep: a ≠ b, 
pgeo-incident: a I b, 
pgeo-leq: a ≡ b, 
pgeo-join: p ∨ q, 
pgeo-dual: pg*, 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
all: ∀x:A. B[x]
Lemmas referenced : 
basic-projective-plane_wf, 
rec_select_update_lemma, 
pgeo-dual_wf2, 
pgeo-join-to-line
Rules used in proof : 
voidEquality, 
voidElimination, 
isect_memberEquality, 
sqequalRule, 
hypothesis, 
hypothesisEquality, 
isectElimination, 
thin, 
dependent_functionElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
cut, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}g:BasicProjectivePlane.  \mforall{}p,q:Line.  \mforall{}l:Point.  \mforall{}s:p  \mneq{}  q.    (l  I  p  {}\mRightarrow{}  l  I  q  {}\mRightarrow{}  p  \mwedge{}  q  \mequiv{}  l)
Date html generated:
2018_05_22-PM-00_35_48
Last ObjectModification:
2017_11_25-AM-09_11_39
Theory : euclidean!plane!geometry
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