Nuprl Lemma : trivial-lengths-equal
∀[e:BasicGeometry]. ∀[a,b:Point].  (|aa| = |bb| ∈ Length)
Proof
Definitions occuring in Statement : 
geo-length: |s|
, 
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
, 
squash: ↓T
, 
prop: ℙ
, 
basic-geometry: BasicGeometry
, 
euclidean-plane: EuclideanPlane
, 
true: True
, 
subtype_rel: A ⊆r B
, 
uimplies: b supposing a
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
Lemmas referenced : 
equal_wf, 
squash_wf, 
true_wf, 
geo-length-type_wf, 
trivial-zero-length, 
geo-length_wf, 
geo-mk-seg_wf, 
subtype_rel_self, 
iff_weakening_equal, 
geo-zero-length_wf, 
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, 
applyEquality, 
thin, 
lambdaEquality, 
sqequalHypSubstitution, 
imageElimination, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
equalityTransitivity, 
hypothesis, 
equalitySymmetry, 
universeEquality, 
setElimination, 
rename, 
natural_numberEquality, 
sqequalRule, 
imageMemberEquality, 
baseClosed, 
instantiate, 
because_Cache, 
independent_isectElimination, 
productElimination, 
independent_functionElimination, 
isect_memberEquality, 
axiomEquality
Latex:
\mforall{}[e:BasicGeometry].  \mforall{}[a,b:Point].    (|aa|  =  |bb|)
Date html generated:
2018_05_22-AM-11_55_58
Last ObjectModification:
2018_04_10-PM-04_35_44
Theory : euclidean!plane!geometry
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