isEdge -- determines if an edge is in a (hyper)graph

Synopsis

• Usage:

  b = isEdge(H,E)

  b = isEdge(H,M)

• Inputs:
  • H, a hypergraph,
  • E, a list, of vertices
  • M, a ring element, a monomial representing an edge
• Outputs:
  • b, a Boolean value, true iff E (or support M) is an edge of H

Description

i1 : S = QQ[z_1..z_8];

i2 : h = hyperGraph {z_2*z_3*z_4,z_6*z_8,z_7*z_5,z_1*z_6*z_7,z_2*z_4*z_8};

i3 : edges h

o3 = {{z , z , z }, {z , z }, {z , z , z }, {z , z , z }, {z , z }}
        2   3   4     5   7     1   6   7     2   4   8     6   8

o3 : List

i4 : isEdge (h,{z_2,z_4,z_8})

o4 = true

i5 : isEdge (h,z_2*z_3*z_4)

o5 = true

i6 : isEdge (h,{z_1,z_2})

o6 = false

See also

• getEdgeIndex -- finds the index of an edge in a HyperGraph