syntex for 'patch' card

[Satyabrata Das]

Dear Everybody,
               I am refining a MR model ( four molecule in the asymmetric 
unit e.g. A,B,C and D ) by X-PLOR (Version 3.851). There are two di-sulfide
bridges in each chain.
What is the correct syntex for 'patch' card ?

******************************************************************************

 {===>}                                               {*Create S-S bridges.*}
  patch disu
    reference=1=( resid 23 )
    reference=2=( resid 55 )
  end
  patch disu
    reference=1=( resid 125 )
    reference=2=( resid 144 )
  end
*****************************************************************************


 {===>}                                               {*Create S-S bridges.*}
  patch disu
    reference=1=( segid A and resid 23 )
    reference=2=( segid A and resid 55 )
  end
  patch disu
    reference=1=( segid A and resid 125 )
    reference=2=( segid A and resid 144 )
  end
***************************************************************************

I am just started learning X-plor, please help me.
Thanks in advance.
Satya