*
* $Id: c205body.inc,v 1.1.1.1 1996/02/15 17:49:07 mclareni Exp $
*
* $Log: c205body.inc,v $
* Revision 1.1.1.1  1996/02/15 17:49:07  mclareni
* Kernlib
*
*
#ifndef CERNLIB_KERNNUM_C205BODY_INC
#define CERNLIB_KERNNUM_C205BODY_INC
*
*
* c205body.inc
*
      LOGICAL MFLAG,RFLAG
      EXTERNAL F
 
      PARAMETER (ONE = 1, HALF = ONE/2)
 
      XA=MIN(A,B)
      XB=MAX(A,B)
      FA=F(XA,1)
      FB=F(XB,2)
      IF(FA*FB .GT. 0) GO TO 5
      MC=0
 
    1 X0=HALF*(XA+XB)
      R=X0-XA
      EE=EPS*(ABS(X0)+1)
      IF(R .LE. EE) GO TO 4
      F1=FA
      X1=XA
      F2=FB
      X2=XB
 
    2 FX=F(X0,2)
      MC=MC+1
      IF(MC .GT. MXF) GO TO 6
      IF(FX*FA .GT. 0) THEN
       XA=X0
       FA=FX
      ELSE
       XB=X0
       FB=FX
      END IF
 
    3 U1=F1-F2
      U2=X1-X2
      U3=F2-FX
      U4=X2-X0
      IF(U2 .EQ. 0 .OR. U4 .EQ. 0) GO TO 1
      F3=FX
      X3=X0
      U1=U1/U2
      U2=U3/U4
      CA=U1-U2
      CB=(X1+X2)*U2-(X2+X0)*U1
      CC=(X1-X0)*F1-X1*(CA*X1+CB)
      IF(CA .EQ. 0) THEN
       IF(CB .EQ. 0) GO TO 1
       X0=-CC/CB
      ELSE
       U3=CB/(2*CA)
       U4=U3*U3-CC/CA
       IF(U4 .LT. 0) GO TO 1
       X0=-U3+SIGN(SQRT(U4),X0+U3)
      END IF
      IF(X0 .LT. XA .OR. X0 .GT. XB) GO TO 1
 
      R=MIN(ABS(X0-X3),ABS(X0-X2))
      EE=EPS*(ABS(X0)+1)
      IF(R .GT. EE) THEN
       F1=F2
       X1=X2
       F2=F3
       X2=X3
       GO TO 2
      END IF
 
      FX=F(X0,2)
      IF(FX .EQ. 0) GO TO 4
      IF(FX*FA .LT. 0) THEN
       XX=X0-EE
       IF(XX .LE. XA) GO TO 4
       FF=F(XX,2)
       FB=FF
       XB=XX
      ELSE
       XX=X0+EE
       IF(XX .GE. XB) GO TO 4
       FF=F(XX,2)
       FA=FF
       XA=XX
      END IF
      IF(FX*FF .GT. 0) THEN
       MC=MC+2
       IF(MC .GT. MXF) GO TO 6
       F1=F3
       X1=X3
       F2=FX
       X2=X0
       X0=XX
       FX=FF
       GO TO 3
      END IF
 
    4 R=EE
      FF=F(X0,3)
      RETURN
    5 CALL KERMTR('C205.1',LGFILE,MFLAG,RFLAG)
      IF(MFLAG) THEN
       IF(LGFILE .EQ. 0) WRITE(*,100)
       IF(LGFILE .NE. 0) WRITE(LGFILE,100)
      END IF
      IF(.NOT.RFLAG) CALL ABEND
      R=-2*(XB-XA)
      X0=0
      RETURN
    6 CALL KERMTR('C205.2',LGFILE,MFLAG,RFLAG)
      IF(MFLAG) THEN
       IF(LGFILE .EQ. 0) WRITE(*,101)
       IF(LGFILE .NE. 0) WRITE(LGFILE,101)
      END IF
      IF(.NOT.RFLAG) CALL ABEND
      R=-HALF*ABS(XB-XA)
      X0=0
      RETURN

#endif