[Raziel_]

I'd like to know this too. I experimented a bit but was unable to use ,exec testfunction(param) command. Don't think there's a boolean datatype. Only thing I found was this bit about expression evaluation:

- IF-THEN condition. You can use "<",">","<=",">=","==","<>" to check if
one value is less then other. Use "AND", "OR", "NOT" in boolean expressions.
You cn use "&&" instead of "AND" and "||" instead of "OR". The zero value is
considered FALSE, the non-zero is TRUE.

if this is true then the zero value and non zero value works like a boolean...