 	if(expr->size==0){
 		return copy_cst_expr(expr);
 	}	
-	if(expr->inf_coeff==NULL || expr->sup_coeff==NULL ){
+	if(expr->inf_coeff==nullptr || expr->sup_coeff==nullptr ){
 		return alloc_expr();
 	}
 	//printf("coming here %zu\n",expr->size);

    if (pr) {
	pr->funid = ELINA_FUNID_UNKNOWN;
	free(pr);
	pr = NULL;
    }
}


	size_t i,k;
	double tmp1, tmp2;

	if((fp->input_lexpr!=nullptr) && (fp->input_uexpr!=nullptr)){
		expr =  replace_input_poly_cons_in_uexpr(pr, expr, fp);
	}

	size_t dims = expr->size;
	double res_sup = expr->sup_cst;
	if(expr->inf_coeff==nullptr || expr->sup_coeff==nullptr){
		return 0;
	}
	for(i=0; i < dims; i++){
