@inproceedings{tomita-1989-parsing,
    title = "Parsing 2-Dimensional Language",
    author = "Tomita, Masaru",
    editor = "Tomita, Masaru",
    booktitle = "Proceedings of the First International Workshop on Parsing Technologies",
    month = aug,
    year = "1989",
    address = "Pittsburgh, Pennsylvania, USA",
    publisher = "Carnegy Mellon University",
    url = "https://preview.aclanthology.org/fix-sig-urls/W89-0243/",
    pages = "414--424",
    abstract = "2-Dimensional Context-Free Grammar (2D-CFG) for 2-dimensional input text is introduced and efficient parsing algorithms for 2D-CFG are presented. In 2D-CFG, a grammar rule{'}s right hand side symbols can be placed not only horizontally but also vertically. Terminal symbols in a 2-dimensional input text are combined to form a rectangular region, and regions are combined to form a larger region using a 2-dimensional phrase structure rule. The parsing algorithms presented in this paper are the 2D-Ear1ey algorithm and 2D-LR algorithm, which are 2-dimensionally extended versions of Earley{'}s algorithm and the LR(O) algorithm, respectively."
}