Q* Meaning in Math: Understand the Concept

[r0bHadz]

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.-

 

[SammyS]

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?