1 Apr 2007 08:56:07 -0400

Related articles |
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Grammar for roman numerals msully4321@gmail.com (2007-03-27) |

Re: Grammar for roman numerals martin@gkc.org.uk (Martin Ward) (2007-03-29) |

Re: Grammar for roman numerals boldyrev+nospam@cgitftp.uiggm.nsc.ru (Ivan Boldyrev) (2007-03-29) |

Re: Grammar for roman numerals mailbox@dmitry-kazakov.de (Dmitry A. Kazakov) (2007-03-30) |

Re: Grammar for roman numerals martin@gkc.org.uk (Martin Ward) (2007-03-30) |

Re: Grammar for roman numerals mailbox@dmitry-kazakov.de (Dmitry A. Kazakov) (2007-04-01) |

Re: Grammar for roman numerals DrDiettrich1@aol.com (Hans-Peter Diettrich) (2007-04-01) |

Re: Grammar for roman numerals alex.habar.nam@gmail.com (whiskey) (2007-04-06) |

Re: Grammar for roman numerals dickey@saltmine.radix.net (Thomas Dickey) (2007-04-06) |

Re: Grammar for roman numerals mailbox@dmitry-kazakov.de (Dmitry A. Kazakov) (2007-04-06) |

Re: Grammar for roman numerals DrDiettrich1@aol.com (Hans-Peter Diettrich) (2007-04-08) |

From: | Hans-Peter Diettrich <DrDiettrich1@aol.com> |

Newsgroups: | comp.compilers |

Date: | 1 Apr 2007 08:56:07 -0400 |

Organization: | Compilers Central |

References: | 07-03-095 07-03-107 07-03-119 |

Keywords: | parse |

Posted-Date: | 01 Apr 2007 08:56:07 EDT |

Martin Ward wrote:

*> Taking the most liberal interpretation of the rule "a smaller number*

*> placed before a larger numeral should be subtracted from it,*

*> instead of added to it", every string of numerals has a valid interpretation.*

*> For example, "IXM" is interpreted as as IX (9) subtraced from M (1000)*

*> to give 991.*

That's my understanding as well. Nonetheless I'm not sure of the full

algorithm, with regards to the total sum.

What about "IXIM"? Intuitively this would be 990 (-(-I+X+I)+M), but it

might be calculated as (-I+X)+(-I+M) = 1008 as well.

Similarly: "IXX" vs. "XIX", where "IX" is a smaller number, and "XI" is

not a smaller number, than the following numeral "X".

*> This method has the advantage of providing representations for zero*

*> and negative numbers: for example VVX is one representation of zero,*

*>*

*> If only the Romans had followed the Robustness Principle, they might*

*> have discovered zero and negative numbers, and changed the course*

*> of mathematical history!*

Great ideas :-)

DoDi

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