@@ -107,10+107,10 @@ satisfies the following constraints, for any finite natural number `n`:
n ^ inf == inf
leq n inf == true
n ^ inf == inf
leq n inf == true
- (Note, though, that with some notions of infinite numbers, operations like `+` and `*` are defined in such a way that `inf + n` is different from `n + inf`, and does exceed `inf`.)
+ (Note, though, that with *some* notions of infinite numbers, like [[!wiki ordinal numers]], operations like `+` and `*` are defined in such a way that `inf + n` is different from `n + inf`, and does exceed `inf`.)
-9. Prove that `add 1 ξ <~~> ξ`, where `ξ` is the fixed
-point you found in (1). What about `add 2 ξ <~~> ξ`?
+9. Prove that `add ξ 1 <~~> ξ`, where `ξ` is the fixed
+point you found in (1). What about `add ξ 2 <~~> ξ`?
Comment: a fixed point for the successor function is an object such that it
is unchanged after adding 1 to it. It makes a certain amount of sense
Comment: a fixed point for the successor function is an object such that it
is unchanged after adding 1 to it. It makes a certain amount of sense