Nuprl Lemma : common-P_point-intersecting-P_lines2
∀e:EuclideanParPlane. ∀P:P_point(e). ∀L,L1:P_line(e).
  (((¬P_point-line-sep(e;P;L)) ∧ (¬P_point-line-sep(e;P;L1)))
  
⇒ fst(L) \/ fst(L1)
  
⇒ (∀l,m,n:Line.  (l \/ m 
⇒ (l \/ n ∨ m \/ n)))
  
⇒ (∃x:Point. ((x I fst(snd(P)) ∧ x I fst(snd(snd(P)))) ∧ x I fst(L) ∧ x I fst(L1))))
Proof
Definitions occuring in Statement : 
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-incident: p I L
, 
geo-line: Line
, 
geo-point: Point
, 
pi1: fst(t)
, 
pi2: snd(t)
, 
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 : 
geo-colinear: Colinear(a;b;c)
, 
geo-lsep: a # bc
, 
basic-geometry-: BasicGeometry-
, 
geo-incident: p I L
, 
so_apply: x[s1;s2;s3]
, 
so_lambda: so_lambda(x,y,z.t[x; y; z])
, 
append: as @ bs
, 
ge: i ≥ j 
, 
true: True
, 
less_than: a < b
, 
less_than': less_than'(a;b)
, 
le: A ≤ B
, 
nat: ℕ
, 
l_member: (x ∈ l)
, 
subtract: n - m
, 
cons: [a / b]
, 
select: L[n]
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
decidable: Dec(P)
, 
lelt: i ≤ j < k
, 
int_seg: {i..j-}
, 
l_all: (∀x∈L.P[x])
, 
geo-colinear-set: geo-colinear-set(e; L)
, 
geo-line-sep: (l # m)
, 
geo-line: Line
, 
euclidean-plane: EuclideanPlane
, 
geo-plsep: p # l
, 
rev_implies: P 
⇐ Q
, 
squash: ↓T
, 
sq_stable: SqStable(P)
, 
uiff: uiff(P;Q)
, 
geo-eq: a ≡ b
, 
geo-Aparallel: l || m
, 
stable: Stable{P}
, 
cand: A c∧ B
, 
exists: ∃x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
false: False
, 
not: ¬A
, 
top: Top
, 
or: P ∨ Q
, 
prop: ℙ
, 
euclidean-parallel-plane: EuclideanParPlane
, 
uimplies: b supposing a
, 
guard: {T}
, 
uall: ∀[x:A]. B[x]
, 
subtype_rel: A ⊆r B
, 
member: t ∈ T
, 
P_point-line-sep: P_point-line-sep(e;P;L)
, 
pi2: snd(t)
, 
pi1: fst(t)
, 
P_line: P_line(eu)
, 
P_point: P_point(eu)
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
Lemmas referenced : 
common-P_point-intersecting-P_lines, 
geo-line-sep-symmetry, 
not-lsep-iff-colinear, 
geo-lsep_wf, 
geo-colinear_wf, 
geo-colinear-iff, 
geo-intersect-symmetry, 
geo-incident-not-plsep, 
geo-colinear-permute, 
geo-colinear-cycle, 
geo-line-pt-sep, 
euclidean-plane-axioms, 
geo-colinear-transitivity, 
lsep-symmetry, 
list_ind_nil_lemma, 
list_ind_cons_lemma, 
l_member_wf, 
int_term_value_var_lemma, 
int_formula_prop_and_lemma, 
itermVar_wf, 
intformand_wf, 
nat_properties, 
select_wf, 
length_wf, 
lsep-implies-sep, 
nil_wf, 
cons_wf, 
geo-colinear-append, 
istype-less_than, 
istype-le, 
int_formula_prop_less_lemma, 
intformless_wf, 
decidable__lt, 
int_formula_prop_wf, 
int_term_value_constant_lemma, 
int_formula_prop_le_lemma, 
int_formula_prop_not_lemma, 
istype-int, 
itermConstant_wf, 
intformle_wf, 
intformnot_wf, 
full-omega-unsat, 
decidable__le, 
length_of_nil_lemma, 
length_of_cons_lemma, 
geo-colinear-is-colinear-set, 
geo-incident-line, 
lsep-all-sym, 
oriented-plane_wf, 
euclidean-plane-subtype-oriented, 
colinear-lsep', 
geo-point_wf, 
geo-sep-or, 
geo-plsep_functionality, 
sq_stable__incident, 
geo-intersect-unique, 
geo-line-eq_weakening2, 
geo-incident_functionality, 
geo-sep_wf, 
minimal-not-not-excluded-middle, 
minimal-double-negation-hyp-elim, 
not_wf, 
false_wf, 
stable__false, 
geo-plsep_wf, 
geo-incident_wf, 
geo-intersect-lines-iff, 
P_point_wf, 
P_line_wf, 
P_point-line-sep_wf, 
istype-void, 
geoline_wf, 
pi1_wf_top, 
geoline-subtype1, 
geo-intersect_wf, 
geo-primitives_wf, 
euclidean-plane-structure_wf, 
euclidean-plane_wf, 
euclidean-parallel-plane_wf, 
subtype_rel_transitivity, 
euclidean-planes-subtype, 
euclidean-plane-subtype, 
euclidean-plane-structure-subtype, 
geo-line_wf
Rules used in proof : 
dependent_pairEquality_alt, 
inlFormation_alt, 
equalitySymmetry, 
equalityTransitivity, 
int_eqEquality, 
equalityIstype, 
lambdaEquality_alt, 
approximateComputation, 
natural_numberEquality, 
dependent_set_memberEquality_alt, 
setIsType, 
imageElimination, 
baseClosed, 
imageMemberEquality, 
promote_hyp, 
functionEquality, 
unionEquality, 
independent_pairFormation, 
dependent_pairFormation_alt, 
unionElimination, 
independent_functionElimination, 
inhabitedIsType, 
productIsType, 
voidElimination, 
isect_memberEquality_alt, 
independent_pairEquality, 
unionIsType, 
rename, 
setElimination, 
because_Cache, 
independent_isectElimination, 
isectElimination, 
instantiate, 
hypothesis, 
applyEquality, 
hypothesisEquality, 
dependent_functionElimination, 
extract_by_obid, 
introduction, 
cut, 
universeIsType, 
functionIsType, 
sqequalRule, 
thin, 
productElimination, 
sqequalHypSubstitution, 
lambdaFormation_alt, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}e:EuclideanParPlane.  \mforall{}P:P\_point(e).  \mforall{}L,L1:P\_line(e).
    (((\mneg{}P\_point-line-sep(e;P;L))  \mwedge{}  (\mneg{}P\_point-line-sep(e;P;L1)))
    {}\mRightarrow{}  fst(L)  \mbackslash{}/  fst(L1)
    {}\mRightarrow{}  (\mforall{}l,m,n:Line.    (l  \mbackslash{}/  m  {}\mRightarrow{}  (l  \mbackslash{}/  n  \mvee{}  m  \mbackslash{}/  n)))
    {}\mRightarrow{}  (\mexists{}x:Point.  ((x  I  fst(snd(P))  \mwedge{}  x  I  fst(snd(snd(P))))  \mwedge{}  x  I  fst(L)  \mwedge{}  x  I  fst(L1))))
Date html generated:
2019_10_29-AM-09_24_17
Last ObjectModification:
2019_10_18-PM-07_33_49
Theory : euclidean!plane!geometry
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