anchor.diff:  
   \g @see ansfile
   : open-file ( c-addr u fam -- fileid ior )
  -\   >r 2dup parsed 2! r>
  +   >r 2dup parsed 2! r>
      openf ;
   
   \g @see ansfile
  
positive.code:    sourcevar 2! >in off interpret ;
  
  : (finclude)
     to source-id  0 to sourceline#
     source-id ['] intline foreachline ;
  
  
negative.code: 
  \g @see ansfile
  : included  ( i*x c-addr u -- j*x )
     inchook0
     here >r
     r/o open-file throw >r 
     r@ include-file
     r> close-file throw
     r> inchook1 drop ;
  
  \g Include file
  \g @also included
  