/* ---------------------------------------------------------------- */
/* SARAG - Root Counting                                            */
/* by Fabrizio Caruso  modified by Alexandre Le meur and Marie-Françoise Roy              */


/* Verbosity levels */
NONVERBOSE : 0;
SUMMARY : 1;
NORMAL : 2;
VERY : 3;
EXTRA : 4;

padWithZeros(seq,size) :=
  append(seq,makelist(0,i,1,size-length(seq)));

/* signed pseudo-remainder of p divised by q*/
sPsRem(p,q,var):=
if degree(p,var)<degree(q,var) then p
else (if remainder(degree(p,var)-degree(q,var),2)=1 then
remainder(leadCoeff(q,var)**(degree(p,var)-degree(q,var)+1)*p,q,var)
else remainder(leadCoeff(q,var)**(degree(p,var)-degree(q,var)+2)*p,q,var)
) /* end else */
;

/* Signed Remainder Sequence */
sRem(a,b,var) :=
  block([aa,bb,rOld,rNew,quo,res,seq,srsRes],
  
  aa : expandIf(a),
  bb : expandIf(b),

  rOld : aa,
  rNew : bb,
  srsRes : [aa],

  while not(rNew = 0) do
    (
    srsRes : endcons(rNew,srsRes), 

    res : remainder(rOld,rNew,var),

    rOld : rNew,
    rNew : -res
    ), /* end while */
  
  return(srsRes)
  ); /* end proc */



/* Extended Signed Remainder Sequence */
sRemExt(a,b,var) :=
  block([rOld,rNew,uOld,uNew,vOld,vNew,rRes, uRes, vRes,quo,rList,uList,vList,rAux,uAux,vAux],
  
  a : expandIf(a),
  b : expandIf(b),

  rOld : a,
  rNew : b,
  uOld : 1, vOld : 0,
  uNew : 0, vNew : 1,
  rList : [a],
  uList : [uOld],
  vList : [vOld],

  while not(rNew = 0 ) do
     (
     rList : endcons(rNew,rList),
     uList : endcons(uNew,uList),
     vList : endcons(vNew,vList),

     rRes : divide(rOld,rNew,var),

     quo : first(rRes),
     
     rAux : rNew,
     uAux : uNew,
     vAux : vNew,

     uNew : ratexpand(-uOld + quo*uNew),
     vNew : ratexpand(-vOld + quo*vNew),

     rOld : rAux,
     uOld : uAux,
     vOld : vAux,
     rNew : -second(rRes)

     ),/* end while */
  return([rList,endcons(uNew,uList),endcons(vNew,vList)])
  );/* end proc */
      

/* It counts the sign change of a determinant after */
/* i consecutive row changes */
revRowsCount(i) := (-1)^(i*(i-1)/2);

/* ------------------------------------------------------- */
/* Part concerning the computation of signed subresultants */


sSubResPol(p,q,var) :=
  block([pp,qq,degA,degB,i,j,k,h,lcA,lcB,delta,
         SR,s,sOld,res],
    
    pp : expandIf(p),
    qq : expandIf(q),
    
    degA : degree(pp,var),
    degB : degree(qq,var),
    if degA<=degB then
      (
      print("sSubRes) Error: inconsistent degrees"),
      return(false)
      ), /* end if */
    
    SR : make_array('any,degA+1),
    s : make_array('any,degA+1),
    sOld : make_array('any,degA+1),


    lcA : leadCoeff(pp,var),
    lcB : leadCoeff(qq,var),

    SR[degA] : pp,
  s[degA] : 1,
      
    sOld[degA] : 1,

    SR[degA-1] : qq,
    sOld[degA-1] : lcB,

    i : degA + 1,
    j : degA,

    while j>=1 and not(SR[j-1]=0) do
      (
      
      k : degree(SR[j-1],var),
     
      if k = j-1 then
        (
        s[j-1] : sOld[j-1],
        
        if k>=1 then
           SR[k-1] : NORM_ALGORITHM(-remainder(s[j-1]^2*SR[i-1],SR[j-1],var)/
                         (s[j]*sOld[i-1]))
        ), /* end if */
      if k < j-1 then
        (
        /* Computation of s[k] */
        for delta : 1 thru min(j-k-1,j-1) do
           sOld[j-delta-1] : (-1)^delta * (sOld[j-1]*sOld[j-delta])/s[j],
        s[k] : sOld[k],
        s[j-1] : 0,
        SR[k] : NORM_ALGORITHM(s[k]*SR[j-1]/sOld[j-1]),
        
        for h : k+1 thru j-2 do
          (
          SR[h] : 0,
          s[h] : 0
          ), /* end for */
        
        /* Computation of SR[k-1] */
        /* ratexpand or expand */
        if k>= 1 then 
          SR[k-1] : NORM_ALGORITHM(-remainder(sOld[j-1]*s[k]*SR[i-1],
                                             SR[j-1],var)/
                         (s[j]*sOld[i-1]))
        ), /* end if */
      
      if k>= 1 then
         sOld[k-1] : leadCoeff(SR[k-1],var),
      i : j,
      j : k
   
      ), /*end while */


res : padWithZeros(makelist(SR[degA-i],i,0,degA-j),degA+1),

     return(res)
 ); /* end proc */



sSubResCoeff(p,q,var) :=
block([s,pp,qq],
pp:expand(p),
qq:expand(q),
s :  sSubResPol(pp,qq,var),
return(
makelist(coeff(s[j],var,degree(pp,var)+1-j),j,1,degree(pp,var)+1)
)
);



/* Extended Signed Subresultant Sequence      */
/* Algorithm 8.75                             */
/* (A variation of this algorithm is used in  */
/* Algorithm 9.47 and Algorithm 10.17         */


/* Extended Signed Subresultant Sequence*/

sSubResExt(a,b,var) :=
  sSubResExtVerbose(a,b,var,DEFAULT_VERBOSITY);

sSubResExtVerbose(a,b,var,verbosity) :=
   block([q,degA,degB,i,j,k,lcA,lcB,delta,
          SR:make_array('any),s:make_array('any),sOld:make_array('any),
          u:make_array('any),v:make_array('any)],
   
   a : expandIf(a),
   b : expandIf(b),
  
   degA : degree(a,var),
   degB : degree(b,var),
   if degA<=degB then
      (
      print("sSubResExt) Error: inconsistent degrees"),
      return(false)
      ),


   SR : make_array('any,degA+1),
   s : make_array('any,degA+1),
   sOld : make_array('any,degA+1),
   u : make_array('any,degA+2),
   v : make_array('any,degA+2),


   lcA : leadCoeff(a,var),
   lcB : leadCoeff(b,var),

   SR[degA] : a,


      s[degA] : 1,
      
   sOld[degA] : s[degA],
   SR[degA-1] : b,
    
   sOld[degA-1] : lcB,

   u[degA+1] : 1,
   v[degA+1] : 0,
   u[degA-1+1] : 0,
   v[degA-1+1] : 1,

   i : degA + 1,
   j : degA,
  
   while j>=1 and not(SR[j-1]=0) do
     (
     k : degree(SR[j-1],var),
     if verbosity>=EXTRA then
        (
        print("sSubResExt) j : ", j),
        print("sSubResExt) k : ", k)
        ),
     if k = j-1 then
       (
       
       s[j-1] : sOld[j-1],
       q : quotient(s[j-1]^2 * SR[i-1], SR[j-1],var),
       if verbosity >= VERY then
         print("sSubResExt) q : ", q),

       if k>=1 then                
         SR[k-1] : NORM_ALGORITHM((-s[j-1]^2 * 
                                 SR[i-1] + q * SR[j-1])/(s[j]*sOld[i-1])),
         
        
       u[k-1+1] : NORM_ALGORITHM((-s[j-1]^2 * 
                                u[i-1+1] + q * u[j-1+1])/(s[j]*sOld[i-1])),
       v[k-1+1] : NORM_ALGORITHM((-s[j-1]^2 * 
                                v[i-1+1] + q * v[j-1+1])/(s[j]*sOld[i-1]))
        
       ),

     if k<j-1 then
       ( 
       s[j-1] : 0,
       /*  Computation of s[k] */ 
       for delta : 1 thru min(j-k-1,j-1) do
          sOld[j-delta-1] : (-1)^delta * (sOld[j-1]*sOld[j-delta])/s[j],
             
       if k>=0 then
         (
         s[k] : sOld[k],
             
         SR[k] : NORM_ALGORITHM(s[k]*SR[j-1]/sOld[j-1])
         ),
       u[k+1] : NORM_ALGORITHM(s[k]*u[j-1+1]/sOld[j-1]),
       v[k+1] : NORM_ALGORITHM(s[k]*v[j-1+1]/sOld[j-1]),
         
        
       for h : k+1 thru j-2 do
          (
          SR[h] : 0,
          u[h+1] : 0,
          v[h+1] : 0,
          s[h] : 0
          ),
     
       /* Computation of SR[k-1], u[k-1], v[k-1] */ 
       q : quotient(s[k]*sOld[j-1]*SR[i-1],SR[j-1],var),
       if k>=1 then
         SR[k-1] : NORM_ALGORITHM((-sOld[j-1] * s[k] * SR[i-1] + 
                           q * SR[j-1])/(s[j]*sOld[i-1])),
   
       u[k-1+1] : NORM_ALGORITHM((-sOld[j-1] * s[k] * u[i-1+1] + 
                           q * u[j-1+1])/(s[j]*sOld[i-1])),
       v[k-1+1] : NORM_ALGORITHM((-sOld[j-1] * s[k] * v[i-1+1] + 
                          q * v[j-1+1])/(s[j]*sOld[i-1]))
         
       ),

     if k>=1 then     
        sOld[k-1] : leadCoeff(SR[k-1],var),
     i : j,
     j : k,
      
     if verbosity>= NORMAL and k>= 1 then
        print("sSubResExt) SR[", k-1,"] : ", SR[k-1])
     ),
for h : 0 thru j-2 do
   (
   SR[h] : 0,
   s[h] : 0,
   u[h+1] : 0,
   v[h+1] : 0
   ),


  s[degA]:lcA,

return(
       [padWithZeros(makelist(SR[degA-i],i,0,degA-j),degA+1),
        makelist(u[degA-i+1],i,0,degA-j+1),
        makelist(v[degA-i+1],i,0,degA-j+1)])
);


/* last non zero element of a sequence */

lastNonZero(seq) :=
block([i],
  for i:1 thru length(seq) do
    if not(seq[length(seq)-i+1] = 0) then
      return(seq[length(seq)-i+1])
);  /* end proc */

/* index of last non zero element of a sequence */
lastNonZeroIndex(seq) :=
block([i],
  for i:1 thru length(seq) do
    if not(seq[length(seq)-i+1] = 0) then
      return(length(seq)-i+1)
);  /* end proc */

/* index of first non zero element of a sequence */
firstNonZeroIndex(seq) :=
block([i],
  for i:1 thru length(seq) do
    if not(seq[i] = 0) then
      return(i)
);  /* end proc */
         
/* Gcd and Gcd-Free part computation */
/* It outputs : */
/* gcd(p,q) and p/gcd(p,q) */

gcdFreePart(p,q,var) :=
block([r],
r:sSubResExt(ratexpand(p),sPsRem(ratexpand(q),ratexpand(p),var),var),
return ([lastNonZero(r[1]),lastNonZero(r[3])])
); /* end proc */


gcdFreePartWithZ(p,q,var) :=
block([r,u,v,c],
r:sSubResExt(p,sPsRem(ratexpand(q),ratexpand(p),var),var),
c:leadCoeff(expand(p),var),
v:lastNonZero(r[3]),
return ([ratexpand(c*lastNonZero(r[1])/leadCoeff(lastNonZero(r[1]),var)),ratexpand(c*v/leadCoeff(v,var))])
); /*  end proc */



sSubResCoeffLast(p,q,var) :=
  last(sSubResCoeff(p,q,var));

sylvesterResultant(p,q,var) :=
  block([aux,pp ,qq],
    pp : expandIf(p),
    qq : expandIf(q),
    if degree(pp,var)>degree(qq,var) then
      return(epsilon(degree(pp,var))*sSubResCoeffLast(pp,qq,var))
    else
      if degree(pp,var)<degree(qq,var) then
        return((-1)^(degree(pp,var)*degree(pp,var))*sylvesterResultant(qq,pp,var))
      else
        (
        aux : expand(leadCoeff(pp,var)*qq-leadCoeff(qq,var)*pp),
       
        return(expand(epsilon(degree(pp,var))*sSubResCoeffLast(pp,aux,var)/leadCoeff(pp,var)^degree(aux,var)))
        ) /* end else */
      ); /* end proc */



subDiscr(p,var) :=
  block([pcRes,pRes,cRes],
    pcRes : sSubRes(p,diff(p,var),var),
    pRes : first(pcRes/leadCoeff(expand(p),var)),
    pRes : cons(first(pRes),expand(rest(pRes)/leadCoeff(expand(p),var))),
    cRes : second(pcRes),
    cRes :  cons(first(cRes),expand(rest(cRes)/leadCoeff(expand(p),var))),
    return([pRes,cRes])
    ); /* end proc */

subDiscrCoeff(p,var):=
  block([cRes],
  cRes : sSubResCoeff(p,diff(p,var),var),
  cRes : cons(first(cRes)/leadCoeff(expand(p),var),expand(rest(cRes)/leadCoeff(expand(p),var))),
  return(cRes)
  ); /* end proc */

discriminant(p,var):=
subDiscrCoeff(p,var)[degree(expand(p),var)+1];


/* --------------------------------------------- */
/* Part concerning the signed remainder sequence */

/* In the following S(P,Q) is the signed remainder sequence of P and Q */

/* Number of sign changes (notation "V") */
/* of sequence containing non-zero elements */


nonZeroSignChanges(seq) := 
block([variations,i],
 variations:0,
 if length(seq) > 1 then
   for i:1 thru length(seq)-1 do
     if seq[i]*seq[i+1] < 0 then
       variations:variations+1,
return(variations)
); /* end proc */

signChanges(seq) :=
  nonZeroSignChanges(trimZeros(seq));


/* Number of sign changes of a polynomial at a certain value */
/* Notation "V(P;a)" */
/* We use proposition 2.4 for the signs at infinities */
signChangesAt(seq,var,a) :=
  if a = inf then
     signChanges(makelist(leadCoeff(seq[i],var),i,1,length(seq)))
  else
     if a = -inf then
       signChanges(makelist((-1)^(degree(seq[i],var))*
                            leadCoeff(seq[i],var),i,1,length(seq)))
     else
       signChanges(makelist(subst(a,var,seq[i]),i,1,length(seq)));
/* end proc */


/* Difference between the no. of changes a two points */
/* Notation "V(P;a,b)" */
signChangesDiff(seq,var,a,b) :=
  signChangesAt(seq,var,a) - signChangesAt(seq,var,b);

/* Sign changes of the i-th coefficients of a polynomial */
/* Notation "V(P)" (P is a polynomial) */
signChangesPolyCoeff(poly,var) :=
  signChanges(makelist(coeff(poly,var,i),i,0,degree(poly,var)));

/* Sequence of the derivatives of a polynomial */
/* Notation "Der(P)" */
derSeq(f,var) :=
  makelist(diff(f,var,i),i,0,degree(f,var));

/* Cauchy Index */
/* Theorem 2.52 */
/* V(S(P,Q);a,b) = Ind(Q/P;a,b) */

sRemCauchyIndexBetween(num,den,var,a,b) :=
  signChangesDiff(sRem(den,num,var),var,a,b);

sRemCauchyIndex(num,den,var) :=
  signChangesDiff(sRem(den,num,var),
                      var,-inf,+inf);

/* Tarski query computed by Sylvester's theorem's formula */
/* Theorem 2.55 */
/* V(S(P,P'Q);a,b) = SQ(Q,P;a,b) */

sRemTarskiQueryBetween(q,p,var,a,b) :=
  signChangesDiff(sRem(p,diff(p,var)*q,var),var,a,b);

sRemTarskiQuery(q,p,var) :=
  signChangesDiff(sRem(p,diff(p,var)*q,var),
                       var,-inf,+inf);


/* Number of roots counted by Tarski's theorem's formula */
/* Theorem 2.56 */
/* V(S(P,P');a,b) */
sRemNumberOfRootsBetween(p,var,a,b) :=
  sRemTarskiQueryBetween(1,p,var,a,b);

sRemNumberOfRoots(p,var) :=
  sRemTarskiQuery(1,p,var);

/* Tarski sequence */
/* defined as: S(P,P') */
sturmSequence(p,var) :=
   sRem(p,diff(p,var),var);


/* ------------------------------------------------- */
/* Part concerning signed subresultants coefficients */
/* and the Cauchy Index in all R(Subsection 9.1.2)   */


/* Notation taken from Remark 4.36 and used by Notation 9.4 */
epsilon(x) :=
  (-1)^(x*(x-1)/2);

/* It counts and removes the trailing zeros out of a sequence */

trimZeroCount(seq,count) :=
block([list,count,i],
list:[],
count:0,
if length(seq)>0 then
  for i:1 thru length(seq) do
     if seq[i] = 0 then
count:count+1
     else
list:append(list,[seq[i]]),
return([list,count])
); /* end proc */

/* Interface function */
trimZero(seq) :=
  trimZeroCount(seq,0);



/* Notation 9.4 ("D(s)") */
/* When there are no zeros this gives the difference between */
/* the sign permanencies and the number of sign changes */
 
genPermMVar(seq) :=
block([res,count,i],
  res:0, i:1,
   ( while not(i>length(seq)-1) do
if not(seq[i]=0) then
(count:1,
  (while (seq[i+count]=0 and not(i+count>length(seq)-1)) do count:count+1), /* end while */
    ( if  remainder(count,2)=1 then  
res:res+(-1)^((count)*(count-1)/2)*sgn(seq[i]*seq[i+count])),
i:i+count) /* end if */
else i:i+1), /* end while */
return(res)
); /* end proc */


/* Cauchy Index by signed subresultant */
/* Algorithm 9.27 */

sSubResCauchyIndex(q,p,var) :=
genPermMVar(sSubResCoeff(p,sPsRem(ratexpand(q),ratexpand(p),var),var));

/* Tarski Query by signed subresultant */
/* Algorithm 9.28 */
sSubResTarskiQuery(q,p,var) :=
genPermMVar(sSubResCoeff(p,sPsRem(ratexpand(diff(p,var)*q),p,var),var));

sSubResNumberOfRoots(p,var) :=
sSubResTarskiQuery(1,p,var);



/* ----------------------------------------------  */
/* Part concering the Bezoutian (subsection 9.1.3) */

/* Bezoutian (Notation 9.14) */
bez(p,q,var,x,y) :=
   (subst(y,var,q) * subst(x,var,p) - 
    subst(x,var,q) * subst(y,var,p))/(x-y); /* end proc */



/* ----------------------------------------------- */
/* Part concerning the Cauchy Index on an interval */
/* (Subsection 9.1.5)                              */

/* Modified number of sign changes */
/* Notation 9.29, ("W(s)") */
/* Modified Sign Changes: */
/* counting as two sign changes the groups +,0,0,+ and -,0,0,- */


modifiedSignChanges(seq) := 
block([variations,i],
 variations:signChanges(seq),
 if length(seq) > 1 then
   for i:1 thru length(seq)-3 do
if (seq[i+1]=0 and seq[i+2]=0 and seq[i]*seq[i+3] > 0) then
       variations:variations+2,
return(variations)
); /* end proc */


/* Remove identically zero elements from a list */


removeZeros(seq) :=
block([list,i],
list:[],
if length(seq)>0 then
  for i:1 thru length(seq) do
     if not (seq[i] = 0) then
list:append(list,[seq[i]]),
return(list)
); /* end proc */


/* Modified Sign Changes at a certain value */
/* Notation "W(P;a)" */
modifiedSignChangesAt(seq,var,value) :=
   if value = inf then
      signChanges(makelist(leadCoeff(seq[i],var),i,1,length(seq)))
   else
     if value = -inf then
       signChanges(makelist((-1)^(degree(seq[i],var))*
                            leadCoeff(seq[i],var),i,1,length(seq)))
     else
       modifiedSignChanges(subst(value,var,removeZeros(seq))); /* end proc */


/* Modified Sign Changes Difference */
/* Notation "W(P;a,b)" */
modifiedSignChangesDiff(seq,var,a,b) :=
   modifiedSignChangesAt(seq,var,a)-
   modifiedSignChangesAt(seq,var,b);



/* Cauchy Index in an interval computed by subresultants */
/* Theorem 9.30 */
/* W(SR(P,Q);a,b) = Ind(Q/P;a,b) */

sSubResCauchyIndexBetween(num,den,var,a,b) :=
  modifiedSignChangesDiff(sSubResPol(den,sPsRem(num,den,var),var),var,a,b);

/* Tarski Query by subresultants */
/* Corallary 9.32 */
/* W(SR(P,Remainder(P,Q));a,b) = SQ(Q,P;a,b) */
sSubResTarskiQueryBetween(q,p,var,a,b) :=
  modifiedSignChangesDiff(sSubResPol(p,
                              sPsRem(ratexpand(diff(p,var)*q),p,var),var),var,a,b);

/* Number of roots on an interval by signed subresultants */
/* Consequence of Corollary 9.32 */
sSubResNumberOfRootsBetween(p,var,a,b) :=
  sSubResCauchyIndexBetween(diff(p,var),p,var,a,b);


/* ------------------------------- */
/* Part concerning Hankel Matrices */


/* It computes the signature of a Hankel quadratic form */
/* Algorithm 9.47 */


hankelSignature(seq) :=
  block([m,n,sLen,trimRes,trimmed,count,c,p,q,t,i,SR,j,defective],
   sLen : length(seq),
   if evenp(sLen) then
     (
     print("hankelSignature) Number of elements must be odd"),
     return(false)
     ), /* end if */
   n : (sLen+1)/2,

   trimRes : trimZero(seq),

   if length(trimRes) = 0 then
      return(0)
   else
       c:firstNonZeroIndex(seq),
      (if c>=n then
         (if oddp(c) then 
            return(sgn(seq[c]))
         else
            return(0)) /* end if */
        else m:lastNonZeroIndex(seq),
         (if m <= n then
           (if oddp(2*n-m) then
              return(sgn(seq[m])) 
           else
              return(0)) /* end if */
         else
           (
           p : t^m,
           q : sum(seq[i]*t^(m-i),i,1,m),

           SR : sSubResPol(p,q,t),

           /* check of defectiveness */
           j : m-n,
           defective : true,
           while defective do
              if degree(SR[m-j+1],t) = j then
                 defective : false
              else 
                 j : j-1,

           return(genPermMVar(
                   makelist(sSubResCoeff(p,q,t)[i],
                     i,1,m-j+1))) 

           ) /* end else */
         ) /* end if */
         
      ) /* end if */
   
); /* end proc */


/* It build a Hankel matrix out of an odd-numbered sequence */
hankelMatrix(seq) :=
  block([n,len],
  len : length(seq),
  n : (len+1)/2,
  return(makelist(
           makelist(
                  seq[i+j+1],
               j,0,n-1),
           i,0,n-1)
         )
  ); /* end proc */



/* ----------------------------------------------------- */
/* Part concerning complex roots with negative real part */


evenPart(pol,var) :=
  sum(ratcoeff(pol,var,i*2)*var^i,
      i,0,floor(degree(pol,var)/2));

oddPart(pol,var) :=
  sum(ratcoeff(pol,var,i*2+1)*var^i,
      i,0,ceiling(degree(pol,var)/2));

lienardChipartConditions(pol,var) :=
  block([F,G,SR,degP,m],
  F : evenPart(pol,var),
  
  G : oddPart(pol,var),

  degP : degree(pol,var),

  if evenp(degP) then
    (
    m = p/2,
    SR : sSubResCoeff(F,G,var),

    return(setify(append(poly2list(pol,var),SR)))
    ) /* end if */
  else
    (
    m = (p-1)/2,
    SR : sSubResCoeff(var*G,F,var),

    return(setify(append(poly2list(pol,var),SR)))
    ) /* end else */
); /* end proc */
     



/* It computes the difference between the number of roots of P */
/* with positive real parts and the number of roots with negative real parts */
/* Theorem 9.48 (notation "n(P)") */
posNegDiff(a,var) :=
  block([p,degP,m,f,g,i],
  p : expandIf(a),
  degP : degree(p,var),
  
  if evenp(degP) then
     (
     m : degP/2,
     f : sum(coeff(p,var,i*2)* var^i,i,0,m),
     g : sum(coeff(p,var,i*2+1)*var^i,i,0,m-1),
    

     return(-sSubResCauchyIndex(g,f,var)+
             sSubResCauchyIndexBetween(sPsRem(var*g,f,x),f,var))
     ) /* end if */
  else
     ( 
     m : (degP-1)/2, 
     f : sum(coeff(p,var,i*2)* var^i,i,0,m),
     g : sum(coeff(p,var,2*i+1)* var^i,i,0,m),
     

     return(-sRemCauchyIndexBetween(f,NORM_ALGORITHM(var*g),
            var,-inf,+inf)+
             sRemCauchyIndexBetween(f,g,
            var,-inf,+inf))
     ) /* end else */
  ); /* end proc */

  /* New name for Horner evaluation */

hornerEval(pol,var,value) :=saragHorner(pol,var,value) ;

saragHorner(pol,var,value) :=
  block([res,i,degP],

  degP : degree(pol,var),
  
  res : leadCoeff(pol,var),

  for i : 1 thru degP do
     res : value*res+ratcoeff(pol,var,degP-i),

  return(res) 
  ); /* end proc */
