anchor.diff:  c
   c...  subroutine arguments
   c
  -      integer numnp,neq,nhist,nstep,lastep,ierr
  +      integer numnp,neq,nconcflag,nhist,nstep,lastep,ierr
         integer id(ndof,numnp),ibond(ndof,numnp)
         character errstrng*(*)
  -      double precision bond(ndof,numnp),b(neq),d(ndof,numnp)
  -      double precision deld(ndof,numnp),histry(nhist,lastep+1),deltp
  +      double precision bond(ndof,numnp),bconcforce(neq*nconcflag)
  +      double precision d(ndof,numnp),deld(ndof,numnp)
  +      double precision histry(nhist,lastep+1),deltp
   c
   c...  local variables
   c
  
positive.code: c
            else if(itype.eq.ithree) then
              k=id(i,j)
              if(nstep.eq.izero) then
                b(k)=bond(i,j)
                if(ihist.ne.izero) b(k)=bond(i,j)*histry(ihist,1)
              else if(nstep.ge.ione) then
                if(ihist.ne.izero) b(k)=bond(i,j)*(histry(ihist,nstep+1)
       &                                 -histry(ihist,nstep))
              end if
            end if
          end do
        end do
  
negative.code: c~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  c
  c
        subroutine load(id,ibond,bond,d,deld,bconcforce,histry,deltp,
       & numnp,neq,nconcflag,nhist,nstep,lastep,ierr,errstrng)
  c
  c...program to transfer nodal boundary conditions into appropriate
  c   vectors:
  c
  c        bconcforce(neq) = concentrated nodal forces applied to global
  c                          right hand vector.
  c        d(ndof,numnp) = global displacements (fixed or zero
  c                        displacements)
  c        deld(ndof,numnp)= changes in displacement (constant velocity)
  