Nuprl Lemma : Euclid-erect-perp-on-same-side
∀e:EuclideanPlane. ∀a:Point. ∀b:{b:Point| a ≠ b} . ∀c:{c:Point| Colinear(a;b;c)} . ∀q:{q:Point| q # ab} .
  (∃p:Point [(ab  ⊥c pc ∧ p # ab ∧ (p leftof ab 
⇐⇒ q leftof ab))])
Proof
Definitions occuring in Statement : 
geo-perp-in: ab  ⊥x cd
, 
euclidean-plane: EuclideanPlane
, 
geo-lsep: a # bc
, 
geo-colinear: Colinear(a;b;c)
, 
geo-left: a leftof bc
, 
geo-sep: a ≠ b
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
sq_exists: ∃x:A [B[x]]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
set: {x:A| B[x]} 
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
euclidean-plane: EuclideanPlane
, 
sq_stable: SqStable(P)
, 
implies: P 
⇒ Q
, 
squash: ↓T
, 
exists: ∃x:A. B[x]
, 
sq_exists: ∃x:A [B[x]]
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
uimplies: b supposing a
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
geo-lsep: a # bc
, 
or: P ∨ Q
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
basic-geometry: BasicGeometry
, 
not: ¬A
, 
false: False
Lemmas referenced : 
sq_stable__geo-lsep, 
Euclid-erect-2perp, 
set_wf, 
geo-point_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geo-lsep_wf, 
geo-colinear_wf, 
geo-sep_wf, 
lsep-all-sym2, 
geo-left_wf, 
geo-perp-in_wf, 
iff_wf, 
not-left-and-right
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
setElimination, 
thin, 
rename, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
hypothesisEquality, 
hypothesis, 
because_Cache, 
independent_functionElimination, 
sqequalRule, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
productElimination, 
isectElimination, 
applyEquality, 
instantiate, 
independent_isectElimination, 
lambdaEquality, 
unionElimination, 
dependent_set_memberFormation, 
independent_pairFormation, 
productEquality, 
voidElimination
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a:Point.  \mforall{}b:\{b:Point|  a  \mneq{}  b\}  .  \mforall{}c:\{c:Point|  Colinear(a;b;c)\}  .  \mforall{}q:\{q:Point| 
                                                                                                                                                                          q  \#  ab\}  .
    (\mexists{}p:Point  [(ab    \mbot{}c  pc  \mwedge{}  p  \#  ab  \mwedge{}  (p  leftof  ab  \mLeftarrow{}{}\mRightarrow{}  q  leftof  ab))])
Date html generated:
2018_05_22-PM-00_09_27
Last ObjectModification:
2018_04_04-PM-07_08_08
Theory : euclidean!plane!geometry
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