Q* Meaning in Math: Understand the Concept

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The discussion centers around the meaning of ℚ* in mathematics, specifically in the context of a problem from Grimaldi's discrete math book. Participants are trying to clarify whether ℚ* represents the set of non-zero rational numbers, as the book does not define the symbol. There is confusion about whether ℚ* includes both positive and negative rational numbers. The main question is whether the intersection of ℚ* and ℤ equals ℤ. Clarification on this notation is essential for solving the homework problem.
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Homework Statement


In Grimaldis discrete math book he asks

Determine which of the statements are true which are false:

ℚ*∩ ℤ = ℤ

Homework Equations

The Attempt at a Solution


he never explained in his book what * represents.

I tried google "what does Q* mean in mathematics" and "Q* in mathematics" with no luck. Does anyone know what he means with *? My first thought was its both Q+ and Q- but I don't think it is -l.-
 
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I believe that ℚ* is the set of non-zero rational numbers. (According to the Appendix)

Do you have a copy of Grimaldi's textbook?
 
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