Consider the following ml code:

one <- 1
two < one + 1

function add val
    print two + val

The variable two declared by assigning the result of an expression to it, and is accessed in function add, it should be a global variable to allow the access. But in C, you can not use expression when declaring a global variable like:

double one = 1;
double two = one + 1;

To address this issue, I tried to declare it outside of main function, without appoint a value to it:

double one = 1;
double two;

and then in main method, before any other statement, change its value:

two = one + 1;

It can be done like this, but a little bit tricky, and I wonder if it is the original intension of the project or just nobody has thought of it.