Nuprl Lemma : pgeo-three-lines_wf
∀g:ProjectivePlaneStructure. ∀a:Point.
  (pgeo-three-line-axiom(a) ∈ ∃l,m,n:Line. (a I l ∧ a I m ∧ a I n ∧ l ≠ m ∧ m ≠ n ∧ n ≠ l))
Proof
Definitions occuring in Statement : 
pgeo-three-lines: pgeo-three-line-axiom(p), 
projective-plane-structure: ProjectivePlaneStructure, 
pgeo-lsep: l ≠ m, 
pgeo-incident: a I b, 
pgeo-line: Line, 
pgeo-point: Point, 
all: ∀x:A. B[x], 
exists: ∃x:A. B[x], 
and: P ∧ Q, 
member: t ∈ T
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
member: t ∈ T, 
pgeo-three-lines: pgeo-three-line-axiom(p), 
projective-plane-structure: ProjectivePlaneStructure, 
record+: record+, 
record-select: r.x, 
subtype_rel: A ⊆r B, 
eq_atom: x =a y, 
ifthenelse: if b then t else f fi , 
btrue: tt, 
uall: ∀[x:A]. B[x], 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
prop: ℙ, 
or: P ∨ Q, 
implies: P ⇒ Q, 
and: P ∧ Q, 
exists: ∃x:A. B[x]
Lemmas referenced : 
subtype_rel_self, 
all_wf, 
pgeo-line_wf, 
pgeo-point_wf, 
sq_stable_wf, 
pgeo-plsep_wf, 
or_wf, 
pgeo-lsep_wf, 
pgeo-lpsep_wf, 
pgeo-psep_wf, 
exists_wf, 
pgeo-incident_wf, 
projective-plane-structure_subtype, 
projective-plane-structure_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
sqequalRule, 
sqequalHypSubstitution, 
dependentIntersectionElimination, 
dependentIntersectionEqElimination, 
thin, 
hypothesis, 
applyEquality, 
tokenEquality, 
introduction, 
extract_by_obid, 
isectElimination, 
lambdaEquality, 
hypothesisEquality, 
setEquality, 
setElimination, 
rename, 
functionEquality, 
productEquality, 
because_Cache, 
functionExtensionality
Latex:
\mforall{}g:ProjectivePlaneStructure.  \mforall{}a:Point.
    (pgeo-three-line-axiom(a)  \mmember{}  \mexists{}l,m,n:Line.  (a  I  l  \mwedge{}  a  I  m  \mwedge{}  a  I  n  \mwedge{}  l  \mneq{}  m  \mwedge{}  m  \mneq{}  n  \mwedge{}  n  \mneq{}  l))
Date html generated:
2018_05_22-PM-00_32_10
Last ObjectModification:
2017_11_03-AM-11_50_07
Theory : euclidean!plane!geometry
Home
Index