anchor.diff:  c~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   c
   c
  -      subroutine eforce(xl,sh,shj,det,gauss,evp,p,iel,nen,ngauss,ierr,
  -     & getshape,bmatrix)
  +      subroutine eforce(xl,sh,shj,det,gauss,evp,p,iel,nen,ngauss,
  +     & getshape,bmatrix,ierr,errstrng)
   c
   c...this subroutine computes the effective forces at each node
   c   within an element: p=(b)t*evp, where p is the local force vector,
  
positive.code: c...  subroutine arguments
  c
        integer iel,nen,ierr
        double precision xl(nsd,nen),sh(nsd+1,nenmax,ngaussmax)
        double precision shj(nsd+1,nenmax,ngaussmax),det(ngaussmax)
        double precision gauss(nsd+1,ngaussmax),evp(nstr,ngauss)
  
negative.code: c
        nee=ndof*nen
        call getshape(xl,sh,shj,shd,shbar,det,gauss,vol,iel,nen,ngauss,
       & ierr,errstrng)
        if(ierr.ne.izero) return
  c
        do l=1,ngauss
  