@Generable(description: "A mathematical symbol or structured construct.")
indirect enum MathToken: Equatable {
    case integer(Int)
    case real(Double)
    case identifier(String)
    case constant(MathConstantToken)
    
    case plus
    case minus
    case multiplication(MultiplicationSymbol)
    case division
    case power
    case modulo
    case factorial
    
    case transpose
    case inverse
    case determinant
    
    case leftParen
    case rightParen
    
    case equal
    case lessThan
    case lessThanOrEqual
    case greaterThan
    case greaterThanOrEqual
    case notEqual
    
    case matrix(elements: [[[MathToken]]])
    case vector(elements: [[MathToken]], orientation: VectorOrientationToken)
    
    case functionApplication(function: [MathToken], arguments: [[MathToken]])
    
    case derivative(expression: [MathToken], variable: MathToken, order: Int)
    case partialDerivative(expression: [MathToken], variables: [MathToken])
    case integral(integrand: [MathToken], variable: MathToken, bounds: IntegralBoundsToken)
    
    case gradient(expression: [MathToken], variables: [MathToken])
    case jacobian(expression: [MathToken], variables: [MathToken])
    
    case sum(expression: [MathToken], variable: MathToken, lowerBound: [MathToken], upperBound: [MathToken])
    case product(expression: [MathToken], variable: MathToken, lowerBound: [MathToken], upperBound: [MathToken])
    case limit(expression: [MathToken], variable: MathToken, approaches: [MathToken], direction: LimitDirectionToken)
    
    case equationSystem(equations: [[MathToken]])
    case constraintSystem(relations: [[MathToken]])
}