Nuprl Lemma : geo-between-middle-or

e:BasicGeometry. ∀a,b,c,d:Point.  (a ≠  b ≠  b ≠  a_b_d  a_c_d  (b_c_d ∨ c_b_d))


Proof




Definitions occuring in Statement :  basic-geometry: BasicGeometry geo-between: a_b_c geo-sep: a ≠ b geo-point: Point all: x:A. B[x] implies:  Q or: P ∨ Q
Definitions unfolded in proof :  all: x:A. B[x] implies:  Q member: t ∈ T uall: [x:A]. B[x] subtype_rel: A ⊆B guard: {T} uimplies: supposing a prop: and: P ∧ Q not: ¬A false: False or: P ∨ Q iff: ⇐⇒ Q basic-geometry: BasicGeometry euclidean-plane: EuclideanPlane basic-geometry-: BasicGeometry- exists: x:A. B[x] stable: Stable{P} geo-eq: a ≡ b cand: c∧ B
Lemmas referenced :  geo-between_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 geo-sep_wf geo-point_wf geo-sep-sym geo-strict-between-sep3 iff_weakening_uiff not_wf not_over_or istype-void geo-between-middle geo-between-sep geo-sep-or geo-strict-between-sep1 subtype_rel_self basic-geometry-_wf geo-proper-extend-exists stable__geo-between double-negation-hyp-elim geo-construction-unicity geo-between-symmetry geo-strict-between-implies-between geo-between-inner-trans extended-out-preserves-between geo-out-iff-between1 euclidean-plane-axioms
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation_alt universeIsType cut introduction extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality applyEquality hypothesis instantiate independent_isectElimination sqequalRule because_Cache inhabitedIsType productElimination dependent_functionElimination independent_functionElimination unionEquality productEquality voidElimination functionIsType unionIsType productIsType setElimination rename dependent_set_memberEquality_alt unionElimination inrFormation_alt inlFormation_alt independent_pairFormation

Latex:
\mforall{}e:BasicGeometry.  \mforall{}a,b,c,d:Point.    (a  \mneq{}  b  {}\mRightarrow{}  b  \mneq{}  c  {}\mRightarrow{}  b  \mneq{}  d  {}\mRightarrow{}  a\_b\_d  {}\mRightarrow{}  a\_c\_d  {}\mRightarrow{}  (b\_c\_d  \mvee{}  c\_b\_d))



Date html generated: 2019_10_16-PM-01_24_49
Last ObjectModification: 2019_01_13-PM-00_56_38

Theory : euclidean!plane!geometry


Home Index