org.junit.Assert.assertEquals(top, sem.minus(top, top));
org.junit.Assert.assertEquals(top, sem.minus(top, new Interval(1,2)));
org.junit.Assert.assertEquals(top, sem.minus(top, new Interval(1,Double.POSITIVE_INFINITY)));
org.junit.Assert.assertEquals(top, sem.minus(top, new Interval(Double.NEGATIVE_INFINITY, 3)));
org.junit.Assert.assertEquals(new Interval(Double.NEGATIVE_INFINITY, -2), sem.minus(new Interval(Double.NEGATIVE_INFINITY, -1), new Interval(1,Double.POSITIVE_INFINITY)));
org.junit.Assert.assertEquals(new Interval(Double.NEGATIVE_INFINITY, 2), sem.minus(new Interval(Double.NEGATIVE_INFINITY, 1), new Interval(-1,Double.POSITIVE_INFINITY)));
org.junit.Assert.assertEquals(new Interval(Double.NEGATIVE_INFINITY, -4), sem.minus(new Interval(Double.NEGATIVE_INFINITY, -1), new Interval(3,5)));
org.junit.Assert.assertEquals(new Interval(4, Double.POSITIVE_INFINITY), sem.minus(new Interval(3,5), new Interval(Double.NEGATIVE_INFINITY, -1)));
org.junit.Assert.assertEquals(new Interval(4, Double.POSITIVE_INFINITY), sem.minus(new Interval(3,Double.POSITIVE_INFINITY), new Interval(-100, -1)));
org.junit.Assert.assertEquals(new Interval(Double.NEGATIVE_INFINITY,-4), sem.minus(new Interval(-100, -1), new Interval(3,Double.POSITIVE_INFINITY)));