Nuprl Lemma : perp-aux-separations
∀e:HeytingGeometry. ∀a,b,c,x,c1,c',p:Point.
  ((((c # ba ∧ ab  ⊥x cx) ∧ a ≠ x)
  ∧ ((c=a=c1 ∧ c=x=c') ∧ c'a ≅ ca)
  ∧ c' # c1a
  ∧ ((a # cc' ∧ c1=p=c') ∧ ab  ⊥a pa)
  ∧ p # ab)
  
⇒ ((c' ≠ c1 ∧ c ≠ x ∧ (c' ≠ x ∧ c1 ≠ p) ∧ c' ≠ p ∧ c ≠ c1) ∧ c # c'c1))
Proof
Definitions occuring in Statement : 
geo-triangle: a # bc
, 
heyting-geometry: HeytingGeometry
, 
geo-perp-in: ab  ⊥x cd
, 
geo-midpoint: a=m=b
, 
geo-congruent: ab ≅ cd
, 
geo-sep: a ≠ b
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
member: t ∈ T
, 
guard: {T}
, 
subtype_rel: A ⊆r B
, 
heyting-geometry: HeytingGeometry
, 
euclidean-plane: EuclideanPlane
, 
basic-geometry: BasicGeometry
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
geo-midpoint: a=m=b
, 
uimplies: b supposing a
, 
geo-colinear-set: geo-colinear-set(e; L)
, 
l_all: (∀x∈L.P[x])
, 
top: Top
, 
int_seg: {i..j-}
, 
lelt: i ≤ j < k
, 
le: A ≤ B
, 
less_than': less_than'(a;b)
, 
false: False
, 
not: ¬A
, 
less_than: a < b
, 
squash: ↓T
, 
true: True
, 
select: L[n]
, 
cons: [a / b]
, 
subtract: n - m
Lemmas referenced : 
geo-triangle-property, 
midpoint-sep, 
subtype_rel_self, 
euclidean-plane-structure_wf, 
basic-geo-axioms_wf, 
euclidean-plane-structure-subtype, 
geo-left-axioms_wf, 
geo-sep-sym, 
geo-between-sep, 
geo-triangle-colinear, 
geo-triangle-symmetry, 
geo-colinear-is-colinear-set, 
geo-between-implies-colinear, 
length_of_cons_lemma, 
length_of_nil_lemma, 
false_wf, 
lelt_wf, 
geo-triangle_wf, 
euclidean-plane-subtype, 
heyting-geometry-subtype, 
subtype_rel_transitivity, 
heyting-geometry_wf, 
euclidean-plane_wf, 
geo-primitives_wf, 
geo-perp-in_wf, 
geo-sep_wf, 
geo-midpoint_wf, 
geo-congruent_wf, 
geo-point_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
sqequalHypSubstitution, 
productElimination, 
thin, 
cut, 
introduction, 
extract_by_obid, 
dependent_functionElimination, 
hypothesisEquality, 
independent_functionElimination, 
hypothesis, 
independent_pairFormation, 
applyEquality, 
sqequalRule, 
instantiate, 
isectElimination, 
setEquality, 
productEquality, 
cumulativity, 
because_Cache, 
independent_isectElimination, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
dependent_set_memberEquality, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed
Latex:
\mforall{}e:HeytingGeometry.  \mforall{}a,b,c,x,c1,c',p:Point.
    ((((c  \#  ba  \mwedge{}  ab    \mbot{}x  cx)  \mwedge{}  a  \mneq{}  x)
    \mwedge{}  ((c=a=c1  \mwedge{}  c=x=c')  \mwedge{}  c'a  \00D0  ca)
    \mwedge{}  c'  \#  c1a
    \mwedge{}  ((a  \#  cc'  \mwedge{}  c1=p=c')  \mwedge{}  ab    \mbot{}a  pa)
    \mwedge{}  p  \#  ab)
    {}\mRightarrow{}  ((c'  \mneq{}  c1  \mwedge{}  c  \mneq{}  x  \mwedge{}  (c'  \mneq{}  x  \mwedge{}  c1  \mneq{}  p)  \mwedge{}  c'  \mneq{}  p  \mwedge{}  c  \mneq{}  c1)  \mwedge{}  c  \#  c'c1))
Date html generated:
2017_10_02-PM-07_07_54
Last ObjectModification:
2017_08_16-AM-11_04_52
Theory : euclidean!plane!geometry
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