anchor.diff:  c.... hack; DG interface doesn't support 2nd and higher order
   c
             if(ipord .eq. 1) then
  -            nshlb   = nenbl;
  +            nshlb   = nenbl_if ! only work with linear element
             else if(ipord .gt. 1) then
               write(*,*) "need to implement for higher order"
               call error('elmgmrelas  ','higher order', ipord)
  
positive.code: c
  c.... the 1 side
  c
            lcsyst = lcsyst1
            nenl = nenl1
            nshl = nshl1
  c
  c          if(lcsyst.eq.itp_wedge_tri) lcsyst=nenbl ! may not be necessary
            ngaussb = nintb(lcsyst)
  c
  c.... compute and assemble non-unit normal for side 1
  c
  
negative.code:           ipord   = lcblkif(5, iblk)    ! polynomial order
            nenl0   = lcblkif(6, iblk)    ! number of vertices per element0
            nenl1   = lcblkif(7, iblk)    ! number of vertices per element1
            nenbl_if= lcblkif(8, iblk)    ! number of vertices on the interface
            mater0  = lcblkif(9, iblk)
            mater1  = lcblkif(10,iblk)
            nshl0   = lcblkif(iblkif_nshl0,iblk)
  