anchor.diff:        limit = limit + 1
         goto 10
   	
  - 20   string2 = stringbuf(1:limit-1)
  + 20   if(limit.gt.1) then
  +        string2 = stringbuf(1:limit-1)
  +      else
  +        string2 = ''
  +      endif
   
         return
         end
  
positive.code:          endif
   100  continue
  	   
        islen = 1
        return
        end
  
negative.code:       do 100 i = 1,limit
           string2(i:i) = string1(i:i) 
   100  continue
        string2(limit+1:limit+1) = char(0)
  
        return
        end
  