- We have an average income per capita. Everybody with an income lower than 0.7 of the average income per capita is just allowed to use currency B.
- Additional everybody who is owning more value/money/goods 2.0 of the average income per capita is just allowed to use currency A.
- It is forbidden to exchange both currency with each other.
- All goods and services are pegged on the value (A+B)/2 ----- (Currency A plus Currency B divided by two)
- Every year every person is rated which currency the person can use.
So you have two currencies with different inflation rates, A's value is bound to deteriorate faster than B's value, so people will keep B instead of A, whatever the punishment will be for violating the rules. There will be a de-pegging event of goods and services, people will use B instead of A for the economy.
The economy isn't something you can tightly control, that's why centrally planned countries failed, and de-pegging events happened.