@startuml
Context <- AbstractExpression
Context <-- Client
AbstractExpression <-- Client
AbstractExpression <|- TerminalExpression
AbstractExpression <|-- NonterminalExpression
AbstractExpression <--* NonterminalExpression

interface AbstractExpression {
  {abstract} +Interpret(Context)
}
class TerminalExpression {
  +Interpret(Context)
}
class NonterminalExpression {
  -children : List<AbstractExpression>
  +Interpret(Context)
}

hide empty attributes
hide empty methods
@enduml