Nuprl Lemma : symmetric-point-construction
∀e:BasicGeometry. ∀a,p:Point.  (a ≠ p 
⇒ (∃p':Point. p=a=p'))
Proof
Definitions occuring in Statement : 
basic-geometry: BasicGeometry
, 
geo-midpoint: a=m=b
, 
geo-sep: a ≠ b
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
implies: P 
⇒ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
exists: ∃x:A. B[x]
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
basic-geometry: BasicGeometry
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
guard: {T}
, 
uimplies: b supposing a
, 
euclidean-plane: EuclideanPlane
, 
sq_stable: SqStable(P)
, 
squash: ↓T
Lemmas referenced : 
sympoint_wf, 
geo-sep_wf, 
geo-midpoint_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
basic-geometry-subtype, 
subtype_rel_transitivity, 
basic-geometry_wf, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geo-point_wf, 
sq_stable__midpoint
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
dependent_pairFormation_alt, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
dependent_set_memberEquality_alt, 
hypothesis, 
universeIsType, 
applyEquality, 
because_Cache, 
sqequalRule, 
lambdaEquality_alt, 
setElimination, 
rename, 
inhabitedIsType, 
equalityTransitivity, 
equalitySymmetry, 
instantiate, 
independent_isectElimination, 
dependent_functionElimination, 
independent_functionElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
equalityIsType1
Latex:
\mforall{}e:BasicGeometry.  \mforall{}a,p:Point.    (a  \mneq{}  p  {}\mRightarrow{}  (\mexists{}p':Point.  p=a=p'))
Date html generated:
2019_10_16-PM-01_15_09
Last ObjectModification:
2018_11_08-PM-01_16_32
Theory : euclidean!plane!geometry
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