Nuprl Lemma : geo-le-congruent
∀g:BasicGeometry. ∀a,b,c,d:Point.  ((|ab| ≤ |cd| ∧ |cd| ≤ |ab|) 
⇒ ab ≅ cd)
Proof
Definitions occuring in Statement : 
geo-le: p ≤ q
, 
geo-length: |s|
, 
geo-mk-seg: ab
, 
basic-geometry: BasicGeometry
, 
geo-congruent: ab ≅ cd
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
basic-geometry: BasicGeometry
, 
euclidean-plane: EuclideanPlane
, 
uimplies: b supposing a
, 
uiff: uiff(P;Q)
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
guard: {T}
Lemmas referenced : 
geo-le_antisymmetry, 
geo-length_wf, 
geo-mk-seg_wf, 
geo-congruent-iff-length, 
geo-le_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, 
lambdaFormation_alt, 
sqequalHypSubstitution, 
productElimination, 
thin, 
cut, 
introduction, 
extract_by_obid, 
dependent_functionElimination, 
hypothesisEquality, 
isectElimination, 
setElimination, 
rename, 
hypothesis, 
because_Cache, 
independent_isectElimination, 
equalitySymmetry, 
sqequalRule, 
productIsType, 
universeIsType, 
inhabitedIsType, 
applyEquality, 
instantiate
Latex:
\mforall{}g:BasicGeometry.  \mforall{}a,b,c,d:Point.    ((|ab|  \mleq{}  |cd|  \mwedge{}  |cd|  \mleq{}  |ab|)  {}\mRightarrow{}  ab  \mcong{}  cd)
Date html generated:
2019_10_16-PM-01_36_13
Last ObjectModification:
2018_10_03-PM-00_05_03
Theory : euclidean!plane!geometry
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