General schematic a top-down parser begins by pushing the start symbol onto the stack It accepts an input string if, after a series of actions, the stack and the input become empty A general schematic for a successful top-down parse S Start Symbol Inputstring s //one of the two actions one of the two actions acceGeneral Schematic • A top-down parser begins by pushing the start symbol onto the stack • It accepts an input string if, after a series of actions, the stack and the input become empty • A general schematic for a successful top-down parse: $ StartSymbol Inputstring$ … … //one of the two actions … … //one of the two actions $ $ accept