I dont understand in 1.38. how (x, x, y, y) and (x, x, x, y) sum into (x, x, y, z)
x+x= x i could see how that makes sense under the interpretation that a sum of x and x don't expand the possible scope of x because it is itself.
x+y = y doesnt really make sense unless x = 0..
or unless its also x + y = x
neither of which i think is something theyre trying to convey.
y+y= z contradicts the first idea unless x = 0
so.... does x=0? or is there something im missing?