anchor.diff:  
          NNODE=M
        NNB=NNODE-NNF
  -     write(11,*)  ' NNB=',NNB,' NNF=',NNF,' NNODE=',NNODE
  -     write(11,*) 
  +    ! write(11,*)  ' NNB=',NNB,' NNF=',NNF,' NNODE=',NNODE
  +     !write(11,*) 
   !
   ! ===========================================================
   !
  
positive.code: 
      end subroutine
  
  !       MESHFS4 + MESHBD 
  !
  !C *******************************************************************
  
negative.code:        INTEGER IEB,IEL,IND,I,K,L,M,N,KK,NN,NND0
       REAL(8) X,Y,Z,DX,DY,DZ,DR2,tmp1,tmp2,tmp3,tol
  
          !C ------------------------------------------------------------
          !C  NELEM : total number of elements 
          !C  NELEMF: total number of elements 
          !C  NELEMB: total number of elements 
          !C
          !C  NNODE : total number of nodes 
          !C  NNF   : total number of nodes on the free surface 
          !C  NNB   : total number of nodes on the body surface
          !C ------------------------------------------------------------
          !C    
          !C ** check nodes' situation 
            
  
          !WRITE(6,*) '  Inside CONVSB'
          !write(11,*) '  Inside CONVSB'
          !write(11,*) '  NELEMF=',NELEMF, '  NELEMB=',NELEMB
       
       
          !DO  IEL=1, NELEMF+NELEMB
           !   write(11,1000) IEL,NCN(IEL)
           !   write(11,1100) (XYZE(1,K,IEL),K=1,NCN(IEL))
           !   write(11,1100) (XYZE(2,K,IEL),K=1,NCN(IEL))
           !   write(11,1100) (XYZE(3,K,IEL),K=1,NCN(IEL))     
          !ENDDO
       
  1100    FORMAT(8E15.6)
       
       
        M=0
  
        IF (NELEMF .EQ. 0) THEN
          NNF=0
        ELSE
  
          DO 200 IEL=1,  NELEMF
              DO 180 I=1, NCN(IEL)
  
                  X=XYZE(1,I,IEL)
                  Y=XYZE(2,I,IEL)
                  Z=XYZE(3,I,IEL)
                  !========check coincident node
                  DO 150 L=1, M
                      tmp1 = DABS( X-XYZTP(1,L) )
                      tmp2 = DABS( Y-XYZTP(2,L) )
                      tmp3 = DABS( Z-XYZTP(3,L) )
                      tol = 1.0E-04
                 IF((tmp1.LT.tol).AND.(tmp2.LT.tol).AND.(tmp3.lt.tol)) THEN
                   NCON(IEL, I)=L
                   GOTO 180
                      END IF
   150           CONTINUE
  
  !C ** if the point (XPM, YPM) does not concide with any other
  !C    points had been checked,  give a new code
  !C
               M=M+1
               NCON(IEL, I)=M
               ! a new node matrix,xyztp 
               XYZTP(1,M)=X
               XYZTP(2,M)=Y
               XYZTP(3,M)=Z
  