## For reals

The most recent SMBC:

Though I'm a long-time fan of SMBC, and especially grateful for the math jokes, I feel that this one is slightly spoiled by the questionable use of the term "Discrete Mathematics". As Wikipedia explains

Discrete mathematics is the study of mathematical structures that are fundamentally discrete rather than continuous. In contrast to real numbers that have the property of varying "smoothly", the objects studied in discrete mathematics – such as integers, graphs, and statements in logic – do not vary smoothly in this way, but have distinct, separated values. Discrete mathematics therefore excludes topics in "continuous mathematics" such as calculus and analysis. Discrete objects can often be enumerated by integers. More formally, discrete mathematics has been characterized as the branch of mathematics dealing with countable sets (sets that have the same cardinality as subsets of the natural numbers, including rational numbers but not real numbers). However, there is no exact, universally agreed, definition of the term "discrete mathematics." Indeed, discrete mathematics is described less by what is included than by what is excluded: continuously varying quantities and related notions.

The SMBC aftercomic seems to remove any possibility that "for reals" is meant to be used in a discrete-mathematics context:

Still, …

1. ### Gareth Rees said,

May 17, 2012 @ 12:55 pm

Google Book search suggests that more appropriate fields would be "computer programming" and "foundations of mathematics".

[(myl) Google Scholar gives a slightly different mix.]

2. ### Tom S. Fox said,

May 17, 2012 @ 1:08 pm

Still what?

3. ### Dan Lufkin said,

May 17, 2012 @ 1:12 pm

@Tom
Waters run deep?

4. ### Eric said,

May 17, 2012 @ 1:18 pm

My guess was that he was conflating discrete mathematics with set theory or formal logic, perhaps for reasons to do with the content of introductory courses in discrete math. My recollection from my community college days is that the discrete math course offered by the math department covered much of the same content as the introductory logic course offered by the philosophy department, which, if you don't think too hard about the meaning of "discrete", might lead you to a concept of the field encompassing proofs about the set of reals. On the other hand, as I only took the philosophy course, this is guesswork based on hearsay, and should be accordingly salted to taste.

5. ### Ben Zimmer said,

May 17, 2012 @ 1:18 pm

While we're killing the humor, we could question the labeling of the other set in the Venn diagram. Though for reals shows up occasionally in rap lyrics, I'm not sure it's ever been primarily identified as a rap thing — as opposed to, say, hells yeah/no. An Urban Dictionary contributor calls it "California speak," and Lexicalist seems to bear out the regional focus.

6. ### Jim said,

May 17, 2012 @ 1:39 pm

Of course, the other issue is that the use of "for reals" is actually the union of rap music and discrete math, not the intersection. I think he covered the intersection in his aftercomic.

7. ### suntzuanime said,

May 17, 2012 @ 1:55 pm

Did you miss the recent comic in which he said that a glottal stop was made by halting air flow with your tongue? I would figure that would be a much more "linguistics in the comics" SMBC error.

[(myl) By the time I read it, the comic said "with your glottis"; but Richard Howland-Burton posted a comment on my post on the subject, indicating that around "4:00 a.m. Central" it did specify the tongue as the organ involved. ]

8. ### Jerry Friedman said,

May 17, 2012 @ 2:19 pm

All this time I thought for reals was a New Mexico Hispanic thing. Perhaps I need to hear more slang from other parts of the country. (I still wonder whether it's originally Hispanic—compare de veras and other expressions with plurals that would be singular in English.)

9. ### Mak said,

May 17, 2012 @ 4:23 pm

@Jim

I guess you can interpret the labels as indicating the set of phrases used in Rap music and Discrete mathematics respectively, in which case the phrases used in both will in the intersection.

10. ### Evan said,

May 17, 2012 @ 4:39 pm

I don't think this an appropriate use of a venn diagram. Aren't the circles supposed to be categories, and the things inside the circles to be examples of the categories? This seems to suggest that only rap songs about discrete math involve frequent use of "for reals".

11. ### me said,

May 17, 2012 @ 4:44 pm

It is amusing that neither circle is the best example for either use of "for reals". It would work much better with "kids these days" and "specifications of the domains of functions".

12. ### m.m. said,

May 17, 2012 @ 5:23 pm

Ben Zimmer said

While we're killing the humor, we could question the labeling of the other set in the Venn diagram. Though for reals shows up occasionally in rap lyrics, I'm not sure it's ever been primarily identified as a rap thing — as opposed to, say, hells yeah/no. An Urban Dictionary contributor calls it "California speak," and Lexicalist seems to bear out the regional focus.

The california version came to my mind as well, as I use it frequently, but compared to the 'rap' version, is entirely different in pronunciation: [fɝ ˈɹi.əl(z)] vs [foʊ ˈɹi.əl(z)] (like the UD entry, there exists also an s-less version, compared like anyway vs anyways, and my bias places s-less as older/commoner ie. "are you for real?" vs less common "are you for reals?")

13. ### Pflaumbaum said,

May 17, 2012 @ 6:26 pm

Just in case anyone missed this when it was doing the rounds about five years ago – the legendary maths of hip-hop compendium.

14. ### Ø said,

May 17, 2012 @ 9:46 pm

@Jim: I think that the overlap of two circles = what two things have in common (in this case, what those wacky rappers say and what those wacky math teachers say).

15. ### Roger Lustig said,

May 18, 2012 @ 7:15 am

Whatevs.