Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Translating sentence into symbols

  1. Jan 29, 2015 #1
    I'm having trouble with translating this english sentence into logic symbols.

    The sentence is

    The numbers four and five aren't both prime, but the numbers five and seven are.

    I was thinking ~(F&I)v(IvS) but I really don't know how to deal with the "but".

  2. jcsd
  3. Jan 29, 2015 #2


    Staff: Mentor

    How about just using and?
  4. Jan 29, 2015 #3
  5. Jan 30, 2015 #4


    Staff: Mentor

    I meant the upside down v commonly used in logic for AND. The v itself is used for OR.
  6. Jan 30, 2015 #5


    User Avatar
    Science Advisor
    Gold Member

    Jedishrfu is exactly right. In logic, "but" is equivalent to "and." If you say, for example "x is A but y is B," what you're really saying is "x is A and y is B," and the "but" merely points out that there is some sort of contrast that you want draw the listener's attention to.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook