compare -- compares two elements in a poset

• Usage:

  r = compare(P, a, b)

• Inputs:
  • P, an instance of the type Poset,
  • a, a thing, an element of the poset
  • b, a thing, an element of the poset
• Outputs:
  • r, a Boolean value, whether $a \leq b$ in $P$

i1 : P = poset {{a,b},{a,c}};

i2 : compare(P, a, b)

o2 = true

i3 : compare(P, c, a)

o3 = false

i4 : compare(P, b, c)

o4 = false