Nuprl Lemma : Mid_cases

e:BasicGeometry. ∀A,B,C:Point.  ((B=A=C ∨ C=A=B)  B=A=C)


Proof




Definitions occuring in Statement :  geo-midpoint: a=m=b basic-geometry: BasicGeometry geo-point: Point all: x:A. B[x] implies:  Q or: P ∨ Q
Definitions unfolded in proof :  uimplies: supposing a guard: {T} subtype_rel: A ⊆B uall: [x:A]. B[x] prop: member: t ∈ T or: P ∨ Q implies:  Q all: x:A. B[x]
Lemmas referenced :  Error :basic-geo-primitives_wf,  Error :basic-geo-structure_wf,  basic-geometry_wf subtype_rel_transitivity basic-geometry-subtype geo-point_wf geo-midpoint_wf or_wf geo-midpoint-symmetry
Rules used in proof :  because_Cache sqequalRule independent_isectElimination instantiate applyEquality isectElimination independent_functionElimination hypothesisEquality dependent_functionElimination extract_by_obid introduction cut hypothesis thin unionElimination sqequalHypSubstitution lambdaFormation sqequalReflexivity computationStep sqequalTransitivity sqequalSubstitution

Latex:
\mforall{}e:BasicGeometry.  \mforall{}A,B,C:Point.    ((B=A=C  \mvee{}  C=A=B)  {}\mRightarrow{}  B=A=C)



Date html generated: 2017_10_02-PM-06_33_40
Last ObjectModification: 2017_08_05-PM-04_43_54

Theory : euclidean!plane!geometry


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