Nuprl Lemma : Euclid-drop-perp-00
∀e:EuclideanPlane. ∀a:Point. ∀b:{b:Point| a ≠ b} . ∀c:Point.  ∃x,p:Point. (Colinear(p;x;c) ∧ ab  ⊥p px ∧ x # ab ∧ x ≠ c)
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-sep: a ≠ b
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
and: P ∧ Q
, 
set: {x:A| B[x]} 
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
exists: ∃x:A. B[x]
, 
sq_exists: ∃x:A [B[x]]
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
guard: {T}
, 
uimplies: b supposing a
, 
sq_stable: SqStable(P)
, 
implies: P 
⇒ Q
, 
squash: ↓T
, 
basic-geometry: BasicGeometry
, 
euclidean-plane: EuclideanPlane
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
Lemmas referenced : 
Euclid-drop-perp-0-ext, 
sq_stable__colinear, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
sq_stable__geo-perp-in, 
sq_stable__geo-lsep, 
sq_stable__geo-sep, 
geo-colinear_wf, 
geo-perp-in_wf, 
geo-lsep_wf, 
geo-sep_wf, 
exists_wf, 
geo-point_wf
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
hypothesis, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
productElimination, 
dependent_pairFormation, 
setElimination, 
rename, 
applyEquality, 
instantiate, 
isectElimination, 
independent_isectElimination, 
sqequalRule, 
because_Cache, 
independent_functionElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
independent_pairFormation, 
productEquality, 
lambdaEquality, 
setEquality
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a:Point.  \mforall{}b:\{b:Point|  a  \mneq{}  b\}  .  \mforall{}c:Point.
    \mexists{}x,p:Point.  (Colinear(p;x;c)  \mwedge{}  ab    \mbot{}p  px  \mwedge{}  x  \#  ab  \mwedge{}  x  \mneq{}  c)
Date html generated:
2018_05_22-PM-00_11_29
Last ObjectModification:
2018_05_19-PM-08_48_45
Theory : euclidean!plane!geometry
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