Nuprl Lemma : geo-colinear-left-out3

e:EuclideanPlane. ∀a,b,c,a',c',x,x':Point.
  (Colinear(b;x;x')  a-x-c  a'-x'-c'  out(b aa')  out(b cc')  leftof ac  leftof a'c'  out(b xx'))


Proof




Definitions occuring in Statement :  geo-out: out(p ab) euclidean-plane: EuclideanPlane geo-colinear: Colinear(a;b;c) geo-strict-between: a-b-c geo-left: leftof bc geo-point: Point all: x:A. B[x] implies:  Q
Definitions unfolded in proof :  all: x:A. B[x] implies:  Q member: t ∈ T subtype_rel: A ⊆B uall: [x:A]. B[x] guard: {T} uimplies: supposing a basic-geometry-: BasicGeometry- geo-out: out(p ab) and: P ∧ Q cand: c∧ B not: ¬A geo-eq: a ≡ b prop: iff: ⇐⇒ Q rev_implies:  Q false: False basic-geometry: BasicGeometry geo-strict-between: a-b-c geo-sep: b subtract: m cons: [a b] select: L[n] true: True squash: T less_than: a < b less_than': less_than'(a;b) le: A ≤ B lelt: i ≤ j < k int_seg: {i..j-} top: Top l_all: (∀x∈L.P[x]) geo-colinear-set: geo-colinear-set(e; L)

Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c,a',c',x,x':Point.
    (Colinear(b;x;x')
    {}\mRightarrow{}  a-x-c
    {}\mRightarrow{}  a'-x'-c'
    {}\mRightarrow{}  out(b  aa')
    {}\mRightarrow{}  out(b  cc')
    {}\mRightarrow{}  b  leftof  ac
    {}\mRightarrow{}  b  leftof  a'c'
    {}\mRightarrow{}  out(b  xx'))



Date html generated: 2020_05_20-AM-09_59_23
Last ObjectModification: 2020_01_13-PM-03_43_57

Theory : euclidean!plane!geometry


Home Index