public static Lst <Monomial> Substitute(Lst <Monomial> monomials, Lst <Subst> substs, Style style)
{
if (monomials is Cons <Monomial> cons)
{
return(Monomial.Sum(Substitute(cons.head, substs, style), Substitute(cons.tail, substs, style), style));
}
else
{
return(Monomial.nil);
}
}
public static Lst <Monomial> ToMonomials(Flow flow, Style style)
{
if (flow is NumberFlow num)
{
return(Monomial.Singleton(new Monomial(new NumberFlow(num.value), style)));
}
else if (flow is SpeciesFlow species)
{
return(Monomial.Singleton(new Monomial(new Factor(species))));
}
else if (flow is OpFlow op)
{
if (op.arity == 1)
{
if (op.op == "-")
{
return(ToMonomials(op.args[0], style).Map((Monomial m) => m.Product(Flow.minusOne, style)));
}
}
else if (op.arity == 2)
{
if (op.op == "+")
{
return(Monomial.Sum(ToMonomials(op.args[0], style), ToMonomials(op.args[1], style), style));
}
else if (op.op == "-")
{
return(Monomial.Sum(ToMonomials(op.args[0], style), ToMonomials(op.args[1], style).Map((Monomial m) => m.Product(Flow.minusOne, style)), style));
}
else if (op.op == "*")
{
return(Monomial.Product(ToMonomials(op.args[0], style), ToMonomials(op.args[1], style), style));
}
else if (op.op == "^")
{
if (op.args[1] is NumberFlow exp && IsInt(exp.value) && (int)exp.value >= 0)
{
return(Monomial.Power(ToMonomials(op.args[0], style), (int)exp.value, style));
}
else
{
throw new Error("Polynomial.ToMonomials: " + flow.Format(style));
}
}
else
{
throw new Error("Polynomial.ToMonomials: " + flow.Format(style));
}
}
}