anchor.diff:  c...  apply boundary conditions
   c
   cdebug            write(6,*) "Before load:"
  -            call load(id,ibond,bond,d,deld,btot,histry,deltp,numnp,neq,
  -     &       nhist,nstep,lastep,ierr,errstrng)
  +            call load(id,ibond,bond,d,deld,bconcforce,histry,deltp,
  +     &       numnp,neq,nconcflag,nhist,nstep,lastep,ierr,errstrng)
   cdebug            write(6,*) "After load:"
               if(ierr.ne.izero) return
   c
  
positive.code:               if(ierr.ne.izero) return
  c
                call formdf_ss(
       &         b,neq,                                                   ! force
       &         x,d,dcur,numnp,                                          ! global
       &         s,stemp,                                                 ! stiff
       &         dmat,ien,lm,lmx,infiel,iddmat,ndmatsz,numelt,nconsz,     ! elemnt
  
negative.code: c
              call fill(deld,zero,ndof*numnp)
              call fill(deldx,zero,ndof*numnp)
              call fill(bextern,zero,neq*nextflag)
              call fill(btraction,zero,neq*ntractflag)
              call fill(bconcforce,zero,neq*nconcflag)
  c*            call fill(bintern,zero,neq)
              if(skc) then
                call skclear(idslp,skew,numsn,numnp)
                call skcomp(x,d,skew,idslp,ipslp,ipstrs,numsn,numnp,nstep,
  