Exercise 2.1.2.2.a) PR → RG
b) yes
Exercise 2.1.2.4.{y1,y2,y4}
Exercise 2.1.2.5.a) 2^5=32
b)5^2=25
Exercise 2.1.2.6.whuh?
Exercise 2.1.2.10.a)n!
b)sort-of
Exercise 2.1.2.12.no
Exercise 2.1.2.13.whuh?
Exercise 2.1.2.14.a) {a,b,c,c}
b) {1,4,9,16,25,36,49}
Exercise 2.1.2.16.a)3
b)infinite
c)6 ({0,1,2,3,4,5})
Exercise 2.3.3.1.OK. I'm lost.
I see that child, father, mother are all persons.
I see that child has a mother and a father,
and that mother is female and father is male.
And I haven't a clue what the canonical diagram would be for that.
what it sort-of looks like

More to come.