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# isReflexive -- checks if a Polytope is reflexive

- Usage:
    `b = isReflexive P`
- Inputs:
  - P, a convex polyhedron
- Outputs:
  - b, true if the Polyhedron is reflexive, false otherwise

## Description

A lattice polytope P in the QQ space of a lattice $M$ is reflexive if its polar polytope is also a lattice polytope. The function checks if P is compact, a lattice polytope and if the dual is a lattice polytope.

    i1 : P = convexHull matrix {{1,0,-1},{0,1,-1}}

    o1 = {ambient dimension => 2           }
          dimension of lineality space => 0
          dimension of polyhedron => 2
          number of facets => 3
          number of rays => 0
          number of vertices => 3

    o1 : Polyhedron

    i2 : isReflexive P

    o2 = true

## See also

- isCompact -- checks compactness of a Polyhedron
- isLatticePolytope -- checks if a polyhedron is a lattice polytope
- polar -- computes the polar of a polyhedron

## Ways to use isReflexive:

- `isReflexive(Polyhedron)`

## For the programmer

The object isReflexive is a method function.

The source of this document is in /build/macaulay2-88fgJW/macaulay2-1.25.11+ds/M2/Macaulay2/packages/OldPolyhedra.m2:5818:0.