Who is Sylvia?

[bonanova]

Who is Silvia? what is she,

That all our swains commend her?

Holy, fair, and wise is she;

The heaven such grace did lend her,

That she might admirèd be.

Is she kind as she is fair?

For beauty lives with kindness.

Love doth to her eyes repair,

To help him of his blindness,

And, being helped, inhabits there.

Then to Silvia let us sing,

That Silvia is excelling;

She excels each mortal thing

Upon the dull earth dwelling:

To her let us garlands bring.

William Shakespeare

Let it never be said that the Den does not feed the soul as it exercises the mind.

OK, now the puzzle, compliments of Raymond Smullyan, somewhat of a new hero for me:

There are twin sisters.

One lies and one tells the truth.

One is named Sylvia.

How can you discover which sister is Sylvia by asking one three-word question?

There may be more than one answer.

[TimeSpaceLightForce]

Does Sylvia lie?
truth Sister:Yes
truth Sylvia:No
lying sister:Yes
lying Sylvia:No

[bhramarraj]

Yesterday I was reading Bonanova's head explosion theory....! I think it could be solved by this method.

So a question is to be constructed such that Sylvia whether true or liar, may not be able to answer, while the other who isn't Sylvia is always able to answer.
I hope the question (directed to whomsoever) "Aren't you Sylvia?" is enough to find who is Sylvia.

[TimeSpaceLightForce]

Are you Mia?

[BMAD]

Yesterday I was reading Bonanova's head explosion theory....! I think it could be solved by this method.

So a question is to be constructed such that Sylvia whether true or liar, may not be able to answer, while the other who isn't Sylvia is always able to answer.

I hope the question (directed to whomsoever) "Aren't you Sylvia?" is enough to find who is Sylvia.

"Aren't you Sylvia?" Is a tricky question to ask. If taken literally it is Are not you Sylvia, which doesn't make sense but could casually mean, Are you not Sylvia? (as a split infinitive) and colloquially mean, Are you Sylvia (with the n't added for effect). Meaning that there is ambiguity in how to respond to the question. For which case there is no correct yes/no response unless you know exactly what is implied by the question.

e.g.

"aren't you hungry?"

Meaning 1, i am asking you if you are hungry..How to give a hungry response: -Yes (I am hungry)

Meaning 2, I am asking you if you are not hungry....How to give a hungry response: -No ( I am not not hungry, so i am hungry)

Therefore: ambiguity

Sylvia, want this? **Extending an apple** Since I am talking to Sylvia, only Sylvia whether she tells the truth or not will answer me. The other girl, not spoken to will not speak.

[TimeSpaceLightForce]

Are you twins?

[BMAD]

we don't know if Sylvia tells the truth

Are you twins?

[bonanova]

TSLF has a crisp question. Some of the others might work also.

[BMAD]

Would Sylvia respond to this question?

Does Sylvia lie?

truth Sister:Yes

truth Sylvia:No

lying sister:Yes

lying Sylvia:No

[bonanova]

Would Sylvia respond to this question?

Does Sylvia lie?

truth Sister:Yes

truth Sylvia:No

lying sister:Yes

lying Sylvia:No

Sure. There is a person named Sylvia.

That person has a truth property: Sylvia(Truthful) or Sylvia(Liar).

Any person knowledgable on the subject, (that includes Sylvia) can respond to the question: Sylvia(Liar)?

I was uncertain about these:

"Aren't you Sylvia?" Do you say yes or no truthfully if you are?

"Are you twins?" And "are you Mia?" Don't seem to resolve it.

"Sylvia, want this?" Might decompose to "are you Sylvia AND if so do you want this?" Which the sister could respond to.

[BMAD]

Yes, I guess. Maybe it is because english isn't my native language...but if i was at a party and make a question in the third person, usually the person named wouldn't answer this.

For example: if sara and Diana are standing next to each other and I say.... Does Sara like pets?, it would seem awkward for Sara to answer.

Would Sylvia respond to this question?

Does Sylvia lie?
truth Sister:Yes
truth Sylvia:No
lying sister:Yes
lying Sylvia:No

Sure. There is a person named Sylvia.
That person has a truth property: Sylvia(Truthful) or Sylvia(Liar).
Any person knowledgable on the subject, (that includes Sylvia) can respond to the question: Sylvia(Liar)?

I was uncertain about these:

"Aren't you Sylvia?" Do you say yes or no truthfully if you are?
"Are you twins?" And "are you Mia?" Don't seem to resolve it.
"Sylvia, want this?" Might decompose to "are you Sylvia AND if so do you want this?" Which the sister could respond to.