Why isn’t the instruction being executed?

Question

I am creating a program that sorts a Matrix of structures, first sorts the rows and goes to each row and organizes it by columns. In the matrix I am using after two cycles the value of (i+1 = 4), when I call again the function aux is supposed to (l=4 and r=4) and should not enter inside the if, someone can tell me why?

void aux(int l, int r){
    int i;
    int auxx = 0;
    printf("%d, %d\n", l, r);
    if(l != r){
        for(i = l; i <= r; i++){
            if(matrix[i].line == matrix[i+1].line){auxx = auxx +1;}
            else{
                if(auxx==0){aux(i+1, 4);}
                else{
                    printf("%d\t%d\t%d\t%d\n", i+1, l, auxx+l, 4);
                    bubblec(l, auxx+l);
                    aux(i+1, 4);}
                }
            }
        }   
    }

aux(0, 4);