### Question:
Ln extends Function { public Generic derivative(int n) { return new Inverse(parameters[0]).selfExpand(); } Ln(Generic generic); Generic antiDerivative(int n); Generic derivative(int n); Generic selfExpand(); Generic selfElementary(); Generic selfSimplify(); Generic selfNumeric(); @Nonnull Variable newInstance();  }### Answer:
@Test public void testDerivative() throws Exception { final MathEngine me = JsclMathEngine.getInstance(); assertEquals("1/x", me.simplify("∂(ln(x), x)")); assertEquals("1/(x*ln(2)+x*ln(5))", me.simplify("∂(lg(x), x)")); }