Numbers may contain decimal points. Any fractional part of an exponent is ignored. The top of the stack is popped and stored into a register named x , where x may be any character. If the s is capitalized, x is treated as a stack and the value is pushed on it. The register x is not altered.
All registers start with zero value.
If the l is capitalized, register x is treated as a stack and its top value is popped onto the main stack. The top value on the stack is duplicated. The top value on the stack is printed. The top value remains unchanged. If executing a string, the recursion level is popped by two.