param $COND := true

Rule Main
  output 'o1' or 'o2'
Flow
  rule Init
  rule A
  rule B
  rule C
End

Rule Init
  output 'i1'.touch
End

Rule A
  input 'i1'
  output 'p1' or 'p2'
Flow
  if $COND
    rule A1
  else
    rule A2
  end
End

Rule A1
  output 'p1'.touch
End

Rule A2
  output 'p2'.touch
End

Rule B
  input 'p1'
  output 'o1'.touch
End

Rule C
  input 'p2'
  output 'o2'.touch
End