Newbie - Nested If statements in stored procedure syntax?

What would a nested if statement look like in a stored procedure:

01 If A
02     If B
03        Let x = x + 1
04     Endif B
05     Let y = y + 1
06     Else A
07      If C
08          If D
09              Let z = z + 1
09          Else D
10              Let z = z - 1
11          End D
12      Let ab =  ab + 1
13      End C
14    End A

The original VBA code nests to 9 levels.