public static Lst <Monomial> Sum(Monomial monomial, Lst <Monomial> monomials, Style style)
{
if (monomial.IsZero())
{
return(monomials);
}
if (monomials is Cons <Monomial> cons)
{
if (cons.head.SameFactors(monomial))
{
Flow sumCoeff = OpFlow.Op(cons.head.coefficient, "+", monomial.coefficient).Normalize(style);
if (sumCoeff.IsNumber(0.0))
{
return(cons.tail);
}
else
{
return(Monomial.Cons(new Monomial(sumCoeff, monomial.factors, style), cons.tail));
}
}
else
{
return(Monomial.Cons(cons.head, Sum(monomial, cons.tail, style)));
}
}
else
{
return(Monomial.Singleton(monomial));
}
}
public static Lst <Monomial> Rename(Dictionary <Symbol, SpeciesFlow> dict, Lst <Monomial> monomials, Style style)
{
if (monomials is Cons <Monomial> cons)
{
return(Monomial.Cons(Rename(dict, cons.head, style), Rename(dict, cons.tail, style)));
}
else
{
return(Monomial.nil);
}
}
public static Lst <Monomial> Negate(Lst <Monomial> monomials, Style style)
{
if (monomials is Cons <Monomial> cons)
{
return(Monomial.Cons(cons.head.Product(Flow.minusOne, style), Negate(cons.tail, style)));
}
else
{
return(Monomial.nil);
}
}
public static Lst <Monomial> Substitute(Factor factor, Lst <Subst> substs, Style style)
{
Subst subst = Lookup(factor.variable, substs);
if (subst == null)
{
return(Monomial.Singleton(new Monomial(factor)));
}
else
{
return(Monomial.Power(Monomial.Cons(new Monomial(new Factor(subst.plus)), Monomial.Singleton(new Monomial(Flow.minusOne, new Factor(subst.minus), style))), factor.power, style));
}
}
// ===== Separate =====
public static (Lst <Monomial> positive, Lst <Monomial> negative) Separate(Lst <Monomial> monomials, Style style)
{
if (monomials is Cons <Monomial> cons)
{
(Lst <Monomial> positive, Lst <Monomial> negative) = Separate(cons.tail, style);
int decide = Polynomial.DecideNonnegative(cons.head.coefficient, style);
if (decide == 1)
{
return(Monomial.Cons(cons.head, positive), negative);
}
else if (decide == -1)
{
return(positive, Monomial.Cons(new Monomial(OpFlow.Op("-", cons.head.coefficient), cons.head.factors, style), negative));
}
else
{
throw new Error("MassActionCompiler: aborted because it cannot determine the sign of this expression: " + cons.head.coefficient.Format(style));
}
}
else
{
return(Monomial.nil, Monomial.nil);
}
}
