1 + (1 + 1)
= (1 + 1) + 1, 2 + (1 + 1) =
(2 + 1) + 1, 3 + (1 + 1) =
(3 + 1) + 1
…u.s.w.
1 + (2 + 1)
= (1 + 2) + 1, 2 + (2 + 1) =
(2 + 2) + 1, 3 + (2 + 1) =
(3 + 2) + 1
…u.s.w.
1 + (3 + 1)
= (1 + 3) + 1, 2 + (3 + 1) =
(2 + 3) + 1, 3 + (3 + 1) =
(3 + 3) + 1
…u.s.w.
u.s.w..
So könnte man die Regel
“a + (b + 1) =
(a + b) + 1” anschreiben.