Are the following statements true or false?

**1.** The set of all [math]'s that are in the domain of [math] and where [math] is in the domain of [math] correctly describes the domain of [math].

**2.** If [math] is an element of the domain of [math], then [math] is an element of the domain of [math].

**3.** For any relation [math], it must be that [math] as long as [math] is a constant.

**4.** If [math] is in the domain of [math], then [math] is in the domain of [math].

**5.** If [math], then [math].

**6.** [math] as long as [math] is in both the domain of [math] and in the domain of [math].