Solution: For the two sets in proposition ①, the function f(x)=2x, and x∈N is "order-preserving isomorphism";

For the two sets in proposition ②, you can take the function y =.

nine

2

x？

seven

2

(-1≤x≤3) is "order-preserving isomorphism";

For the two sets in proposition ③, the function tan(πx?

Pi?

2

) (0≤x≤ 1) is an order-preserving isomorphism.

So the answer is 123.