Zillion Notation
Zillion Notation (ZN) is a BEAF-like notation useful for coining -illions similar to the ones in Jonathan Bowers' system.
Definition
Let @ represent any sequence of non-negative integers separated by commas. A valid expression in ZN is of the form z(@). ZN outputs a non-negative integer for every valid expression, determined using this set of rules:
- z() = 0
 - z(a) = 1000a
 - z(@, 0) = z(@)
 - b > 0: z(a, b, @) = z(10^3a, (b-1), @)
 
If none of these rules apply, start the process shown below, starting from the second entry:
- If the entry is 0, then jump to the next entry.
 - If the entry is not 0, then:
                
- Let n equal to this entry, and a equal to the first entry of the input.
 - Decrease n by 1.
 - Change the entry before n to a.
 - Terminate the process.
 
 
Examples
z(x, y) = yth Tier x -illion in Jonathan Bowers' -illion system
z(5, 2)
= z(1000^5, 1)
= z(10^15, 1)
= z(1000^(10^15), 0)
= z(10^(3*10^15), 0)
= 10^(3*10^15 +
            3)
z(5, 1, 1, 2)
= z(5, 1, 5, 1)
= z(5, 1, 5)
= z(5, 5, 4)
= z(1000^5, 4, 4)
...