protected override Expression VisitUnknown(Expression E)
{
Expression LE = Call.L(E, t, s);
// Try applying a rule to E.
Expression TLE = rules.Transform(LE);
if (!ReferenceEquals(TLE, LE))
{
return(TLE);
}
// Try expanding E.
Expression Ex = E.Expand(s);
if (!Equals(E, Ex))
{
return(Visit(Ex));
}
// Try -L(-E, s, t)
// TODO: It would be nice to handle this case in LinearTransform somehow.
Expression NE = Unary.Negate(E);
Expression NEx = NE.Evaluate();
if (!Equals(NE, NEx))
{
return(Unary.Negate(Visit(NEx)));
}
// Give up.
return(LE);
}
public static LazyExpression operator -(Expression L, Expression R)
{
return(new LazyExpression(Sum.New(L, Unary.Negate(R))));
}
static public Expression Subtract(Expression L, Expression R)
{
return(ComputerAlgebra.Sum.New(L, Unary.Negate(R)));
}
public Expression Solve(Expression x)
{
return(Unary.Negate(Sum.New(this.Where(i => !i.Key.Equals(x)).Select(i => Product.New(i.Key, i.Value)))) / this[x]);
}
public static LazyExpression operator -(LazyExpression L, LazyExpression R)
{
return(new LazyExpression(Sum.New(L.value, Unary.Negate(R.value))));
}