In a function call, why is the comma not a sequence point?

Question

In the following code

int main(){  
    int a=3;  
    printf("%d %d %d",++a,a,a++);
    return 0;
}  

As indicated, from the application C99 C :,

The following are the sequence points described in 5.1.2.3:

• A function call after evaluating the arguments (6.5.2.2).
• The end of the first operand of the following operators: logical AND && (6.5.13); logical OR || (6.5.14); conditional? (6.5.15); comma (6.5.17)

The order in which function arguments are evaluated is undefined, as specified in the C standard.

However, in a function call for printf, we have comma-separated arguments that are classified as sequence points. So why does this statement correspond to unspecified behavior?

Answer 1

, . , () .