
typedef int Boolean;
const Boolean TRUE = 1;
const Boolean FALSE = 0;

class Stack {
public:
    Boolean operator == ( Stack &s)
    {
    Boolean r = (index == s.index);
        if( index > 0)
            for( int k = 0; (r == TRUE) && (k < index); k++ )
                r = r && (data[k] == s.data[k]);
        return r;
    }
    ...

