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> It is so much easier if such statements are written as nouns that describe actual things. But there is nothing in 'Sally' or 'Bob' that is more descriptive t
by tpush 8y ago
> It is so much easier if such statements are written as nouns that describe actual things.
But there is nothing in 'Sally' or 'Bob' that is more descriptive than 'a' or 'b' in this case; in fact, using 'Sally' or 'Bob' implies that whatever you're talking about specifically involves people, however that is of course no the case.
Using non-descriptive single letter names makes total sense in a context like this, since the only semantic associated with those particular elements is equivalence.
- all2 8y ago> But there is nothing in 'Sally' or 'Bob' that is more descriptive than 'a' or 'b' in this case; in fact, using 'Sally' or 'Bob' implies that whatever you're talking about specifically involves people, however that is of course no the case. I will trot out "it is standard pedagogical practice..." If someone doesn't have an abstract mental framework (that mathematics and logic require for understanding) to hang stuff like this on, then it is very helpful to restate things in terms that they are familiar with. Once they understand the specific, then its time to make it abstract: take what they now understand and generalize it - say from people, to predicates in general. You gotta start where they're at.
- ken 8y ago> Once they understand the specific, then its time to make it abstract: take what they now understand and generalize it - say from people, to predicates in general. What does "!Bob" mean, though? Are we negating the person, or their name? Neither one makes sense to me. Maybe I'm too far gone down the computer science rabbit hole, but this is far more confusing to me than "!a".
- all2 8y ago> Are we negating the person, or their name? Neither one makes sense to me. This is a fair statement. I think a treatment of predicates would be necessary before getting to using names as predicates. "When we say 'Bob', we mean 'Bob has enough money for a bus fare'." Then, if we want to say "Bob doesn't have enough money for a bus fare" we can express it with !Bob (which means, in this case 'not Bob'). I agree that using names can be confusing. I think meaning needs to be addressed first.
- Izkata 8y agoI don't think you really need to take a detour into discussing meaning if you used meaningful names for the construct, though. For example, since here we're talking about a boolean expression, name the variables like you would boooleans - such as "isBob".