Nuprl Lemma : dist-lemma-lt-2
∀g:EuclideanPlane. ∀a,b,e,f:Point.  (D(a;b;b;b;e;f) ⇒ |ef| < |ab|)
Proof
Definitions occuring in Statement : 
dist: D(a;b;c;d;e;f), 
geo-lt: p < q, 
geo-length: |s|, 
geo-mk-seg: ab, 
euclidean-plane: EuclideanPlane, 
geo-point: Point, 
all: ∀x:A. B[x], 
implies: P ⇒ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
member: t ∈ T, 
uall: ∀[x:A]. B[x], 
euclidean-plane: EuclideanPlane, 
prop: ℙ, 
subtype_rel: A ⊆r B, 
guard: {T}, 
uimplies: b supposing a, 
basic-geometry: BasicGeometry
Lemmas referenced : 
dist_wf, 
geo-point_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geo-add-length-zero2, 
geo-length_wf, 
geo-mk-seg_wf, 
geo-lt_wf, 
dist-lemma-lt
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
universeIsType, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
setElimination, 
rename, 
hypothesisEquality, 
hypothesis, 
inhabitedIsType, 
applyEquality, 
instantiate, 
independent_isectElimination, 
sqequalRule, 
equalitySymmetry, 
hyp_replacement, 
applyLambdaEquality, 
because_Cache, 
dependent_functionElimination, 
independent_functionElimination
Latex:
\mforall{}g:EuclideanPlane.  \mforall{}a,b,e,f:Point.    (D(a;b;b;b;e;f)  {}\mRightarrow{}  |ef|  <  |ab|)
Date html generated:
2019_10_16-PM-02_49_04
Last ObjectModification:
2019_06_05-PM-01_40_31
Theory : euclidean!plane!geometry
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