• 5 Posts
  • 167 Comments
Joined 3 years ago
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Cake day: July 13th, 2023

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  • That’s some awful impressive goalpost shifting. Gold medal mental gymnastics winner.

    And here you are, still unable to explain why prefix and postfix notation don’t have an operator precedence. I’m still waiting.

    I already told you 3 times they obey the same rules

    They literally don’t, and I defy you to show me a single source that tells you that prefix or postfix notation use PEDMAS. I’ll even take Quora answers.
    Heck, I’ll even take a reputable source talking about prefix/postfix that doesnt bring up how order of operations isn’t required for those notations.

    Nope. Doesn’t say that anywhere. Go ahead and screenshot the part which you think says that. I’ll wait

    Right here:

    Infix notation needs extra information to make the order of evaluation of the operators clear:

    rules built into the language about operator precedence and associativity

    Which you attempt to retort with

    BTW this is completely wrong…

    But then you go on to say something to the effect of “anyone who knows the rules can the extra information”. Which is both unsubstantiated given the long history of not having PEDMAS, but also kind of a nothingburger.

    Doesn’t say that either. 🙄 Again, provide a screenshot of where you think it says that

    It’s literally the whole thing. Did you notice how they never discuss the need for operator precedence, or use operator precedence?

    Build for me a prefix or postfix equation that you think is changed by adding parentheses (eg overriding the natural order of operations), and then go ahead and find a prefix or postfix calculator and show me the results of removing those parentheses.
    If you read the rules for those notations, you’ll see pretty clearly that operator precedence is purely positional, and has nothing to do with which operator it is.

    Note that I always cite Maths textbooks

    No, you’ve show a screenshot from a random PDF. What math textbook and what edition is it?

    The fact you think that factorization has to do with order of operations is shocking.
    Yes the multiplication is done first, but not because PEDMAS. The law is about converting between a sum of a common product and a product of sums. No matter how you write them, it will always be about those things, so the multiplication always happens first. It doesn’t depend on PEDMAS because without PEDMAS you’d simply write the equation differently and factorization would still work.
    It’s crazy that you’re not able to distinguish between mathematical concepts and the notation we use to describe them.

    But putting that aside, that’s not a proof of PEDMAS.
    If PEDMAS is an actual law, then there will be a formal proof or theorem about it. There are proofs for 1+1, if PEDMAS is a law then there will be an actual proof specifically about it. Not just some law and then you claim it follows that PEDMAS is true, an actual proof or theorem, or an textbook snippet explain how it is an unprovable statement.




  • Left to right is a convention, yes, doing Multiplication and Division before Addition and Subtraction is a rule 🙄

    A claim entirely unsupported by the textbook example you provided. Nowhere does it say that one is a convention but not the other, it only says that removing brackets changes the meaning in some situations, which is fully within the scope of a convention.

    For the 3rd time it does have order of operations 🙄You just do them in some random order do you?

    There you go again, just admitting you don’t know what postfix and prefix notations are.
    If you’re ordering your operations based what the operator is, like PEDMAS, then what you’re doing isn’t prefix or postfix.

    I’ll tell you what, here is a great free article from Colorado State university talking about prefix, postfix, and infix notations.
    Note how it says the rules about operator precedence are for the notation which itself is a convention, as all notations are, and how prefix and postfix don’t need those rules

    says person who doesn’t know the difference between conventions and rules, and thinks postfix notation doesn’t have rules 🙄

    How embarrassing for you.
    Here are some more materials:

    But to top it all off, if this was truely a law of mathematics, then show me a proof, theorem, or even a mathematical conjecture, about order of operations.










  • Your argument you haven’t made is backed up by math textbooks you haven’t provided written for children.

    What is it that you want addressed?

    How can that specific order of operations be a law of mathematics if it only applies to infix notation, and not prefix or postfix notations? Laws of mathematics are universal across notations.

    Show me a textbook that discusses other notations and also says that order of operations is a law of mathematics.
    You don’t have it, and you also aren’t a maths teacher, or a teacher at all. Just because you say it a lot doesn’t make it true.





  • To a “maths teacher”

    Yeah sure
    A “teacher” who doesn’t know that all lessons are simplifications that get corrected at a higher level, and confidentiality refers to children’s textbook as an infallible source of college level information.

    A “teacher” incapable of differentiating between rules of a convention and the laws of mathematics.

    A “teacher” incapable of looking up information on notations of their own specialization, and synthesizing it into coherent response.

    Uh huh, sounds totally legit