Nuprl Lemma : perp-aux-general-construction
∀e:HeytingGeometry. ∀a,b,c,x:Point.
  (((c # ba ∧ ab  ⊥x cx) ∧ a ≠ x)
  ⇒ (∃c1,c',p:Point. (((c=a=c1 ∧ c=x=c') ∧ c'a ≅ ca) ∧ c' # c1a ∧ ((a # cc' ∧ c1=p=c') ∧ ab  ⊥a pa) ∧ p # ab)))
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], 
exists: ∃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, 
geo-perp-in: ab  ⊥x cd, 
member: t ∈ T, 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
subtype_rel: A ⊆r B, 
guard: {T}, 
uimplies: b supposing a, 
heyting-geometry: HeytingGeometry, 
euclidean-plane: EuclideanPlane, 
basic-geometry: BasicGeometry, 
oriented-plane: OrientedPlane, 
geo-lsep: a # bc, 
or: P ∨ Q, 
geo-triangle: a # bc, 
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, 
exists: ∃x:A. B[x], 
right-angle: Rabc, 
geo-midpoint: a=m=b, 
basic-geometry-: BasicGeometry-, 
uiff: uiff(P;Q), 
cand: A c∧ B, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q, 
geo-strict-between: a-b-c
Lemmas referenced : 
geo-colinear-same, 
geo-triangle_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
heyting-geometry-subtype, 
subtype_rel_transitivity, 
heyting-geometry_wf, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geo-perp-in_wf, 
subtype_rel_self, 
basic-geo-axioms_wf, 
geo-left-axioms_wf, 
geo-sep_wf, 
geo-point_wf, 
lsep-colinear-sep, 
geo-colinear-is-colinear-set, 
length_of_cons_lemma, 
length_of_nil_lemma, 
false_wf, 
lelt_wf, 
geo-proper-extend-exists, 
geo-strict-between-implies-between, 
geo-between-symmetry, 
geo-congruent-iff-length, 
geo-length-flip, 
geo-sep-sym, 
geo-triangle-property, 
geo-triangle-symmetry, 
geo-triangle-colinear, 
geo-strict-between-sep1, 
geo-strict-between-implies-colinear, 
geo-triangle-colinear2, 
geo-strict-between-sep3, 
geo-congruent-mid-exists, 
geo-midpoint_wf, 
geo-congruent_wf, 
exists_wf, 
geo-midpoint-symmetry, 
geo-perp-midsegments, 
midpoint-sep, 
geo-between-implies-colinear, 
geo-colinear_wf, 
right-angle_wf, 
geo-perp-in-iff, 
geo-between-sep, 
perp-aux2
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
sqequalHypSubstitution, 
productElimination, 
thin, 
cut, 
hypothesis, 
dependent_functionElimination, 
hypothesisEquality, 
independent_functionElimination, 
introduction, 
extract_by_obid, 
isectElimination, 
because_Cache, 
productEquality, 
applyEquality, 
instantiate, 
independent_isectElimination, 
sqequalRule, 
setEquality, 
cumulativity, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
dependent_set_memberEquality, 
natural_numberEquality, 
independent_pairFormation, 
imageMemberEquality, 
baseClosed, 
rename, 
equalityTransitivity, 
equalitySymmetry, 
dependent_pairFormation, 
lambdaEquality
Latex:
\mforall{}e:HeytingGeometry.  \mforall{}a,b,c,x:Point.
    (((c  \#  ba  \mwedge{}  ab    \mbot{}x  cx)  \mwedge{}  a  \mneq{}  x)
    {}\mRightarrow{}  (\mexists{}c1,c',p:Point
              (((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)))
Date html generated:
2017_10_02-PM-07_10_12
Last ObjectModification:
2017_08_10-PM-05_08_48
Theory : euclidean!plane!geometry
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