I am not a native English speaker and this question has been bothering me for a long time. I saw this sentence on my text book. However, I don't know what's the meaning of it. And I don't even know whether it's a correct sentence (in terms of syntax). Could somebody help me?
This may be related to the sentence Rose is a rose is a rose is a rose by Gertrude Stein. According to Wikipedia
"A rose is a rose is a rose" is probably her most famous quote, often interpreted as meaning "things are what they are," a statement of the law of identity, "A is A". In Stein's view, the sentence expresses the fact that simply using the name of a thing already invokes the imagery and emotions associated with it.
Quoting Wikipedia again, the law of identity article claims that
In logic, the law of identity states that an object is the same as itself: A ≡ A.
A good example of usage of this is when a government replaces one tax with another.
For example, the old 11% tax was only on goods, but the new 7% tax is on goods and services.
One person says the new tax means people will pay less taxes.
A person could counter and say: "It doesn't matter, really. A tax is a tax is a tax."
Or in other words, what they "call" the tax is irrelevant, and doesn't change the fact that I'm still paying a tax.
Or maybe, a government gets rid of a restaurant tax, but the restaurant adds mandatory tipping.
"A tax is a tax is a tax" would imply that the speaker still feels that he's paying a tax on the food/service. "Call it a tip if you want, a tax is a tax is a tax"