         
         let seqB = PersistentVector<Int>().conj(0).conj(1).conj(2).conj(3).conj(5).conj(6)
         
-        XCTAssert(seqA == seqB, "Sequences not equal")
+        XCTAssert(seqA == seqB)
+        XCTAssert(seqA == seqA)
+        XCTAssert(seqA != seqA.conj(7))
+        XCTAssert(seqA != seqA.assoc(index: 1, 9000))
     }
     
     func testSubVector() {

    
    func testCollection() {
        
        let seq : PersistentVector<Int> = [0,1,3]
        
        XCTAssertEqual(1, seq[1], "subscript")
    }
    
    func testCompare() {

        
        let seq : PersistentVector<Int> = [0,1,3]
        
        let changedSeq = seq
            .assoc(index: 0, 42) // replace existing element
            .assoc(index: 3, 9000) // append new element
        
        XCTAssertEqual("[42, 1, 3, 9000]", changedSeq.description)
        XCTAssertEqual("[0, 1, 3]", seq.description)
    }
    
