loops -- loops of matroid

• Usage:

  loops M

• Inputs:
  • M, a matroid,
• Outputs:
  • a list, the loops of M

i1 : M = matroid({a,b,c,d},{{a,b},{a,c}})

o1 = a "matroid" of rank 2 on 4 elements

o1 : Matroid

i2 : loops M

o2 = {3}

o2 : List

i3 : all(loops M, l -> member(set{l}, circuits M))

o3 = true

i4 : loops(M/(set loops M)) == {}

o4 = true