Nuprl Lemma : geo-perp-in-not-eq
∀e:BasicGeometry. ∀x:Point.  ∀[a,b,c,d:Point].  (ab  ⊥x cd ⇒ (¬a ≡ b))
Proof
Definitions occuring in Statement : 
geo-perp-in: ab  ⊥x cd, 
basic-geometry: BasicGeometry, 
geo-eq: a ≡ b, 
geo-point: Point, 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
not: ¬A, 
implies: P ⇒ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
implies: P ⇒ Q, 
not: ¬A, 
false: False, 
geo-perp-in: ab  ⊥x cd, 
and: P ∧ Q, 
prop: ℙ, 
subtype_rel: A ⊆r B, 
guard: {T}, 
uimplies: b supposing a, 
basic-geometry: BasicGeometry, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q, 
euclidean-plane: EuclideanPlane, 
cand: A c∧ B, 
basic-geometry-: BasicGeometry-, 
geo-eq: a ≡ b
Lemmas referenced : 
geo-eq_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-perp-in_wf, 
geo-point_wf, 
right-angle-legs-same, 
geo-colinear_wf, 
geo-colinear-same, 
geo-colinear_functionality, 
geo-eq_weakening, 
geo-eq_inversion, 
geo-sep-O-X, 
geo-O_wf, 
geo-X_wf, 
geo-eq_transitivity, 
subtype_rel_self, 
basic-geometry-_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
isect_memberFormation, 
introduction, 
cut, 
thin, 
sqequalHypSubstitution, 
productElimination, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
applyEquality, 
because_Cache, 
hypothesis, 
sqequalRule, 
independent_functionElimination, 
voidElimination, 
instantiate, 
independent_isectElimination, 
lambdaEquality, 
dependent_functionElimination, 
isect_memberEquality, 
allFunctionality, 
promote_hyp, 
setElimination, 
rename, 
independent_pairFormation
Latex:
\mforall{}e:BasicGeometry.  \mforall{}x:Point.    \mforall{}[a,b,c,d:Point].    (ab    \mbot{}x  cd  {}\mRightarrow{}  (\mneg{}a  \mequiv{}  b))
Date html generated:
2018_05_22-PM-00_04_45
Last ObjectModification:
2018_04_20-AM-10_20_57
Theory : euclidean!plane!geometry
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