anchor.diff:  c
   c...  local constants
   c
  -      double precision r(10),s(10),t(10),u(10)
  -      data r/ 1d0, 0d0, 0d0, 0d0,0.5d0,0.0d0,0.5d0,0.5d0,0.0d0,0.0d0/
  -      data s/ 0d0, 1d0, 0d0, 0d0,0.5d0,0.5d0,0.0d0,0.0d0,0.5d0,0.0d0/
  -      data t/ 0d0, 0d0, 1d0, 0d0,0.0d0,0.5d0,0.5d0,0.0d0,0.0d0,0.5d0/
  -      data u/ 0d0, 0d0, 0d0, 1d0,0.0d0,0.0d0,0.0d0,0.5d0,0.5d0,0.5d0/
  +c*      double precision r(10),s(10),t(10),u(10)
  +c*      data r/ 1d0, 0d0, 0d0, 0d0,0.5d0,0.0d0,0.5d0,0.5d0,0.0d0,0.0d0/
  +c*      data s/ 0d0, 1d0, 0d0, 0d0,0.5d0,0.5d0,0.0d0,0.0d0,0.5d0,0.0d0/
  +c*      data t/ 0d0, 0d0, 1d0, 0d0,0.0d0,0.5d0,0.5d0,0.0d0,0.0d0,0.5d0/
  +c*      data u/ 0d0, 0d0, 0d0, 1d0,0.0d0,0.0d0,0.0d0,0.5d0,0.5d0,0.5d0/
   c
   c...  intrinsic functions
   c
  
positive.code:       infetype(4)=nee
  c
        do l=1,ngauss
          do i=1,nen
            rr=r(i)*gauss(1,l)
            ss=s(i)*gauss(2,l)
            tt=t(i)*gauss(3,l)
            uu=one-rr-ss-tt
            if(i.le.4) then
              sh(4,i,l)=rr*(two*rr-one)+ss*(two*ss-one)+tt*(two*tt-one)+
       &       uu*(two*uu-one)
              sh(1,i,l)=r(i)*(four*rr-one)-u(i)*(four*uu-one)
              sh(2,i,l)=s(i)*(four*ss-one)-u(i)*(four*uu-one)
              sh(3,i,l)=t(i)*(four*tt-one)-u(i)*(four*uu-one)
            else
              sh(4,i,l)=max(rr,one)*max(ss,one)*max(tt,one)*max(uu,one)
              drr=eight*r(i)*max(ss,one)*max(tt,one)*max(uu,one)
              dss=eight*s(i)*max(rr,one)*max(tt,one)*max(uu,one)
              dtt=eight*t(i)*max(rr,one)*max(ss,one)*max(uu,one)
              duu=(-eight)*u(i)*max(rr,one)*max(ss,one)*max(tt,one)
              sh(1,i,l)=drr-duu
              sh(2,i,l)=dss-duu
              sh(3,i,l)=dtt-duu
            end if
          end do
        end do
        call dcopy(nshsize,sh,ione,shj,ione)
  c
  
negative.code: c
  c...  local variables
  c
  c*      integer nen,ngauss,nec,nee,i,l,nshsize,ngssize
        integer nen,ngauss,nec,nee,l,nshsize,ngssize
  c*      double precision g1,g2,rr,ss,tt,uu,drr,dss,dtt,duu
        double precision g1,g2,rr,ss,tt,uu
        double precision tetvol
  cdebug      integer idb,jdb
  cdebug      double precision dbsum
  c
  cdebug      write(6,*) "Hello from pquadtet_f!"
  c
  c...  definitions
  c
  