Mom, Dad, Baby, Student, Teacher, and Guide are lining up next to each other in six linear spots labeled $1$ to $6,$ one to a spot. Baby needs to line up between Mom and Dad. Student and Teacher need to be next to each other. Guide needs to be at one end, in spot $1$

or $6.$ Formulate this problem as a CSP: list the variables, their domains, and the constraints.

Encode unary constraints as a constraint rather than pruning the domain.