Errors.java

import org.checkerframework.checker.index.qual.GTENegativeOne;
import org.checkerframework.checker.index.qual.LowerBoundUnknown;
import org.checkerframework.checker.index.qual.NonNegative;
import org.checkerframework.checker.index.qual.Positive;

public class Errors {

    void test() {
        int[] arr = new int[5];

        // unsafe
        @GTENegativeOne int n1p = -1;
        @LowerBoundUnknown int u = -10;

        // safe
        @NonNegative int nn = 0;
        @Positive int p = 1;

        //:: error: (array.access.unsafe.low)
        int a = arr[n1p];

        //:: error: (array.access.unsafe.low)
        int b = arr[u];

        int c = arr[nn];
        int d = arr[p];
    }
}
//a comment