Nuprl Lemma : trivial-zero-length
∀[e:BasicGeometry]. ∀[a:Point].  (|aa| = 0 ∈ Length)
Proof
Definitions occuring in Statement : 
geo-length: |s|, 
geo-zero-length: 0, 
geo-length-type: Length, 
geo-mk-seg: ab, 
basic-geometry: BasicGeometry, 
geo-point: Point, 
uall: ∀[x:A]. B[x], 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
rev_implies: P ⇐ Q, 
implies: P ⇒ Q, 
basic-geometry: BasicGeometry, 
uimplies: b supposing a, 
subtype_rel: A ⊆r B, 
guard: {T}
Lemmas referenced : 
geo-zero-length-iff, 
geo-eq_weakening, 
geo-point_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
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
because_Cache, 
productElimination, 
independent_functionElimination, 
isectElimination, 
independent_isectElimination, 
hypothesis, 
applyEquality, 
instantiate, 
sqequalRule, 
isect_memberEquality, 
axiomEquality
Latex:
\mforall{}[e:BasicGeometry].  \mforall{}[a:Point].    (|aa|  =  0)
Date html generated:
2018_05_22-AM-11_55_52
Last ObjectModification:
2018_04_10-PM-04_34_41
Theory : euclidean!plane!geometry
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