Nuprl Lemma : AX3
∀e:EuclideanParPlane. ∀l,m:P_line(e).
  ((P_line-sep(e;l;m) ∧ (∀l,m,n:Line.  (l \/ m ⇒ (l \/ n ∨ m \/ n))))
  ⇒ (∃P:P_point(e). ((¬P_point-line-sep(e;P;l)) ∧ (¬P_point-line-sep(e;P;m)))))
Proof
Definitions occuring in Statement : 
P_line-sep: P_line-sep(eu;L;M), 
P_point-line-sep: P_point-line-sep(e;P;L), 
P_line: P_line(eu), 
P_point: P_point(eu), 
euclidean-parallel-plane: EuclideanParPlane, 
geo-intersect: L \/ M, 
geo-line: Line, 
all: ∀x:A. B[x], 
exists: ∃x:A. B[x], 
not: ¬A, 
implies: P ⇒ Q, 
or: P ∨ Q, 
and: P ∧ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
and: P ∧ Q, 
P_line-sep: P_line-sep(eu;L;M), 
exists: ∃x:A. B[x], 
P_line: P_line(eu), 
P_point: P_point(eu), 
member: t ∈ T, 
prop: ℙ, 
uall: ∀[x:A]. B[x], 
subtype_rel: A ⊆r B, 
guard: {T}, 
uimplies: b supposing a, 
so_lambda: λ2x.t[x], 
euclidean-parallel-plane: EuclideanParPlane, 
so_apply: x[s], 
or: P ∨ Q, 
P_point-line-sep: P_point-line-sep(e;P;L), 
pi2: snd(t), 
pi1: fst(t), 
not: ¬A, 
cand: A c∧ B, 
false: False, 
iff: P ⇐⇒ Q, 
so_lambda: λ2x y.t[x; y], 
so_apply: x[s1;s2], 
top: Top, 
rev_implies: P ⇐ Q, 
geo-Aparallel: l || m, 
geo-line-sep: (l # m), 
uiff: uiff(P;Q), 
geo-plsep: p # l, 
geo-lsep: a # bc, 
stable: Stable{P}
Lemmas referenced : 
P_line-sep_wf, 
all_wf, 
geo-line_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
euclidean-planes-subtype, 
subtype_rel_transitivity, 
euclidean-parallel-plane_wf, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geo-intersect_wf, 
geoline-subtype1, 
or_wf, 
P_line_wf, 
common-P_point-intersecting-P_lines, 
geo-incident_wf, 
geo-plsep_wf, 
geo-point_wf, 
P_point-line-sep_wf, 
not_wf, 
geo-intersect-lines-iff, 
geo-incident-not-plsep, 
geo-Aparallel_weakening2, 
subtype_quotient, 
geo-Aparallel_wf, 
geo-Aparallel-equiv, 
and_false_l, 
geo-intersect-symmetry, 
geo-incident-line, 
geo-Aparallel_sym, 
stable__false, 
false_wf, 
minimal-double-negation-hyp-elim, 
minimal-not-not-excluded-middle, 
geo-intersect-unique, 
geo-eq_inversion, 
geo-incident-iff-not-plsep, 
geo-incident_functionality, 
geo-line-eq_weakening2, 
common-P_point-parallel-P_lines
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
sqequalHypSubstitution, 
productElimination, 
thin, 
productEquality, 
cut, 
introduction, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
hypothesis, 
dependent_functionElimination, 
applyEquality, 
instantiate, 
independent_isectElimination, 
sqequalRule, 
lambdaEquality, 
because_Cache, 
functionEquality, 
setElimination, 
rename, 
unionElimination, 
independent_functionElimination, 
dependent_pairEquality, 
independent_pairEquality, 
setEquality, 
independent_pairFormation, 
voidElimination, 
dependent_set_memberEquality, 
dependent_pairFormation, 
isect_memberEquality, 
voidEquality
Latex:
\mforall{}e:EuclideanParPlane.  \mforall{}l,m:P\_line(e).
    ((P\_line-sep(e;l;m)  \mwedge{}  (\mforall{}l,m,n:Line.    (l  \mbackslash{}/  m  {}\mRightarrow{}  (l  \mbackslash{}/  n  \mvee{}  m  \mbackslash{}/  n))))
    {}\mRightarrow{}  (\mexists{}P:P\_point(e).  ((\mneg{}P\_point-line-sep(e;P;l))  \mwedge{}  (\mneg{}P\_point-line-sep(e;P;m)))))
Date html generated:
2019_10_16-PM-03_04_52
Last ObjectModification:
2018_08_14-PM-03_26_45
Theory : euclidean!plane!geometry
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