anchor.diff:        COMMON /ZVARS/ E3,F3,G3,H3,P3,Q3
         COMMON /MISC/ D11,Rd,Re,Rk,logRe,logRk,TH
         COMMON /TAG/ thru
  +      if (stdp.lt.0.0d0) then
  +          do 415 i = 1,3
  +              do 416 j = 1,3
  +                  strain(i,j) = 0.0d0
  + 416          continue
  + 415      continue
  +          return
  +      endif
   C----
   C Initialize partial derivative components
   C----
  
positive.code:       COMMON /ZVARS/ E3,F3,G3,H3,P3,Q3
        COMMON /MISC/ D11,Rd,Re,Rk,logRe,logRk,TH
        COMMON /TAG/ thru
  C----
  C Initialize displacement components
  C----
  
negative.code:       COMMON /ZVARS0/ U3,V3,W3
        COMMON /PRODUCTS/ xx,xy,yy,dd,xd,xc,xq,yq,dq,pq
        COMMON /TAG/ thru
  
        if (stdp.lt.0.0d0) then
            do 315 i = 1,3
                do 316 j = 1,3
                    strain(i,j) = 0.0d0
   316          continue
   315      continue
            return
        endif
  C----
        thru = 0
        do 306 i = 1,6
  