When you talk about algebra - one might have to restrict one self to '|' and '&'
-- not use '+'  and '-'
E.g.:
True - True = False   # right !?


Not exactly because - True = + True
So True - True = True + True = True
You have to stay in the algebra the whole time.

# but if:
True+True         = True.
# then
True+True   -False      = True -False   # ????
# here I'm already lost ... I don't think this can be done in a consistent way.

In other words:  a "+" operator  would also need a corresponding "-"
operator, and that will just look funny.  I think if you want algebra,
you should restrict yourself to "|" (or) and "&" (and)

When you make computation in the Bool algebra, you use + and * in every math book. In IT books, you see | and &. As Numpy is scientists oriented, I suppose that the definition of + and * is correct.

Matthieu