Set #? Thing -- test set membership

• Operator: #?

• Usage:

  x#?e

• Inputs:
  • x, a set
  • e, a thing
• Outputs:
  • a Boolean value, whether e is in the set x

i1 : x = set{1,2,3}

o1 = set {1, 2, 3}

o1 : Set

i2 : x#?2

o2 = true

i3 : member(2,x)

o3 = true