1 + (1 + (1 + 1)) = 1 + ((1 + 1) + 1)
a + (b + (c + 1)) = a + ((b + c) + 1) = (a + (b + c)) + 1
also analog
1 + (1 + (1 + 1)) = 1 + ((1 + 1) + 1) = (1 + (1 + 1)) + 1
also brauchte ich als Definitionen:
1 + (1 + 1) = ((1 + 1) + 1
und 1 + ((1 + 1) + 1) = (1 + (1 + 1)) + 1
und
(a + b) + (c + 1) = ((a + b) + c) + 1
(1 + 1) + (1 + 1) = ((1 + 1) + 1) + 1
1 + (1 + 1) = (1 + 1) + 1