anchor.diff:  c
         subroutine elastc(
        & alnz,pcg,zcg,dprev,ja,                                           ! sparse
  -     & bextern,btraction,bgravity,bconcforce,bprestress,bintern,bresid, ! force
  -     & bwork,dispvec,nforce,grav,                                       ! force
  +     & bextern,btraction,bgravity,bconcforce,bintern,bresid,bwork,      ! force
  +     & dispvec,nforce,grav,                                             ! force
        & x,d,deld,dcur,id,iwink,wink,nsysdat,                             ! global
        & ibond,bond,                                                      ! bc
        & dx,deldx,dxcur,diforc,idx,iwinkx,winkx,idslp,ipslp,idhist,       ! slip
        & fault,nfault,dfault,tfault,                                      ! fault
        & s,stemp,                                                         ! stiff
  -     & state,dstate,dmat,ien,lm,lmx,lmf,infiel,iddmat,npar,             ! elemnt
  +     & state,dstate,state0,dmat,ien,lm,lmx,lmf,infiel,iddmat,npar,      ! elemnt
        & ielno,iside,ihistry,pres,pdir,                                   ! tractn
        & prop,mhist,infmat,infmatmod,ismatmod,                            ! materl
        & gauss,sh,shj,infetype,                                           ! eltype
  
positive.code: clater     &   dx,iwinkx,winkx,numslp,numsn,nwinkx,                           ! slip
  clater     &   tfault,numfn,                                                  ! fault
  clater     &   s,stemp,                                                       ! stiff
  clater     &   state,dstate,dmat,ien,lm,lmx,lmf,infiel,iddmat,nstatesz,       ! elemnt
  clater     &   ndmatsz,numelt,nconsz,                                         ! elemnt
  clater     &   prop,mhist,infmat,infmatmod,numat,npropsz,tminmax,             ! materl
  clater     &   gauss,sh,shj,infetype,                                         ! eltype
  clater     &   histry,rtimdat,ntimdat,nhist,lastep,elas_matinit_cmp_ld,       ! timdat
  
negative.code: c
  clater        call iterate(
  clater     &   alnz,pcg,zcg,dprev,ja,                                         ! sparse
  clater     &   bextern,btraction,bgravity,bconcforce,bintern,                 ! force
  clater     &   bresid,bwork,dispvec,nforce,grav,                              ! force
  clater     &   x,d,deld,dcur,id,iwink,wink,nsysdat,                           ! global
  clater     &   dx,deldx,dxcur,idx,iwinkx,winkx,idslp,ipslp,                   ! slip
  clater     &   nfault,dfault,tfault,                                          ! fault
  clater     &   s,stemp,                                                       ! stiff
  clater     &   state,dstate,state0,dmat,ien,lm,lmx,lmf,infiel,iddmat,npar,    ! elemnt
  clater     &   ielno,iside,ihistry,pres,pdir,                                 ! tractn
  clater     &   prop,mhist,infmat,infmatmod,tminmax,                           ! materl
  clater     &   gauss,sh,shj,infetype,                                         ! eltype
  