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
Home
Index