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Operations on Points and Lines

Operations on Points and Lines

p eq q : PlanePt, PlanePt -> BoolElt
True if the points p and q are equal, otherwise false.
p ne q : PlanePt, PlanePt -> BoolElt
True if the points p and q are not equal, otherwise false.
l eq m : PlaneLn, PlaneLn -> BoolElt
True if the lines l and m are equal, otherwise false.
l ne m : PlaneLn, PlaneLn -> BoolElt
True if the lines l and m are not equal, otherwise false.
p in l : PlanePt, PlaneLn -> BoolElt
True if point p lies on the line l, otherwise false.
p notin l : PlanePt, PlaneLn -> BoolElt
True if point p does not lie on the line l, otherwise false.
S subset l : { PlanePt }, PlaneLn -> BoolElt
Given a subset S of the point set of the plane P and a line l of P, return true if the subset S of points lies on the line l, otherwise false.
S notsubset l : { PlanePt }, PlaneLn -> BoolElt
Given a subset S of the point set of the plane P and a line l of P, return true if the subset S of points does not lie on the line l, otherwise false.
l meet m : PlaneLn, PlaneLn -> PlanePt
The unique point common to the lines l and m.
p[i] : PlanePt, RngIntElt -> FldFinElt
The i-th coordinate of the point p, which must be from a classical plane. If p is from a projective plane, then i must satisfy 1 <= i <= 3; if p is from an affine plane, then i must satisfy 1 <= i <= 2.
l[i] : PlaneLn, RngIntElt -> FldFinElt
The i-th coordinate of the line l, which must be from a classical plane. The integer i must satisfy 1 <= i <= 3. Recall that in a classical plane <a:b:c> (where a, b, c in K) represents the line given by the equation ax + by + cz = 0 in a projective plane or ax + by + c = 0 in an affine plane.
IsCollinear(S) : { PlanePt } -> BoolElt, PlaneLn
True if the set S of points of the plane P are collinear, otherwise false. If the points are collinear, the line which they define is also returned.
IsConcurrent(R) : { PlaneLn } -> BoolElt, PlanePt
True if the set R of lines of the plane P are concurrent, otherwise false. If the lines are concurrent, their common point is returned as a second value.
Pencil(p) : PlanePt -> { PlaneLn }
The pencil of lines passing through the point p.
Set(l) : PlaneLn -> { PlanePt }
The set of points contained in the line l.
Support(l) : PlaneLn -> SetEnum
The set of underlying points contained in the line l of a plane P (i.e. the elements of the set have their "real" types; they are no longer a "PlanePt" of P).
Representative(l) : PlaneLn -> PlanePt
Rep(l) : PlaneLn -> PlanePt
Given a line l of the plane P, return a representative point of P which is incident with l.
Random(l) : PlaneLn -> PlanePt
Given a line l of the plane P, return a random point of P which is incident with l.
Slope(l) : PlaneLn -> FldFinElt
The slope of the line l of a classical affine plane P.
IsParallel(l, m) : PlaneLn, PlaneLn -> BoolElt
True if the line l is parallel to the line m in the affine plane P.
ParallelClass(l) : PlaneLn -> { PlaneLn }
The parallel class containing the line l of an affine plane P.
ParallelClasses(P) : AffPl -> { { PlaneLn } }
The partition into parallel classes of the lines of the affine plane P.
ContainsQuadrangle(S) : { PlanePt } -> BoolElt
True if the set S of points of a plane P contains a quadrangle.
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