Rule ExclusiveChoice
  output 'o1' or 'o2'
Flow
  rule Init
  rule B
  rule C
    if $COND
  rule A1
  else
  rule A2
  end

End

Rule Init
  output 'i1'
End

Rule A2
  input 'i1'
  output 'p2'
End

Rule B
  input 'p1'
  output 'o1'
End

Rule C
  input 'p2'
  output 'o2'
End

Rule A1
  input 'i1'
  output 'p1'
End