Nuprl Lemma : eqtri_wf
∀[e:EuclideanPlane]. ∀[a:Point]. ∀[b:{b:Point| a ≠ b} ].
  (Δ(a;b) ∈ {c:Point| ((cb ≅ ab ∧ ca ≅ ba) ∧ ca ≅ cb) ∧ c leftof ab} )
Proof
Definitions occuring in Statement : 
eqtri: Δ(a;b)
, 
euclidean-plane: EuclideanPlane
, 
geo-left: a leftof bc
, 
geo-congruent: ab ≅ cd
, 
geo-sep: a ≠ b
, 
geo-point: Point
, 
uall: ∀[x:A]. B[x]
, 
and: P ∧ Q
, 
member: t ∈ T
, 
set: {x:A| B[x]} 
Definitions unfolded in proof : 
uimplies: b supposing a
, 
guard: {T}
, 
sq_exists: ∃x:A [B[x]]
, 
so_apply: x[s]
, 
and: P ∧ Q
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
all: ∀x:A. B[x]
, 
subtype_rel: A ⊆r B
, 
geo-CC-2, 
Euclid-Prop1-left, 
record-select: r.x
, 
geo-CC: CC(a;b;c;d)
, 
geo-CCL: CCL(a;b;c;d)
, 
eqtri: Δ(a;b)
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
Lemmas referenced : 
geo-primitives_wf, 
euclidean-plane-structure_wf, 
subtype_rel_transitivity, 
euclidean-plane-subtype, 
euclidean-plane-structure-subtype, 
set_wf, 
geo-left_wf, 
geo-congruent_wf, 
sq_exists_wf, 
geo-sep_wf, 
geo-point_wf, 
all_wf, 
euclidean-plane_wf, 
subtype_rel_self, 
Euclid-Prop1-left, 
geo-CC-2
Rules used in proof : 
isect_memberEquality, 
independent_isectElimination, 
equalitySymmetry, 
equalityTransitivity, 
axiomEquality, 
rename, 
setElimination, 
productEquality, 
setEquality, 
lambdaEquality, 
because_Cache, 
hypothesisEquality, 
cumulativity, 
functionEquality, 
isectElimination, 
sqequalHypSubstitution, 
hypothesis, 
extract_by_obid, 
instantiate, 
thin, 
applyEquality, 
sqequalRule, 
cut, 
introduction, 
isect_memberFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}[e:EuclideanPlane].  \mforall{}[a:Point].  \mforall{}[b:\{b:Point|  a  \mneq{}  b\}  ].
    (\mDelta{}(a;b)  \mmember{}  \{c:Point|  ((cb  \mcong{}  ab  \mwedge{}  ca  \mcong{}  ba)  \mwedge{}  ca  \mcong{}  cb)  \mwedge{}  c  leftof  ab\}  )
Date html generated:
2018_05_22-AM-11_53_42
Last ObjectModification:
2018_05_21-AM-01_13_22
Theory : euclidean!plane!geometry
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