piston.asmt file is running correctly

MbDCode/FunctionX.cpp

@@ -1,3 +1,22 @@
 #include "FunctionX.h"
+#include "Constant.h"
 
 using namespace MbD;
+
+MbD::FunctionX::FunctionX(Symsptr arg) : xx(arg)
+{
+}
+
+Symsptr MbD::FunctionX::differentiateWRT(Symsptr var)
+{
+	if (this == var.get()) return std::make_shared<Constant>(1.0);
+	auto dfdx = differentiateWRTx();
+	auto dxdvar = xx->differentiateWRT(var);
+	return Symbolic::times(dfdx, dxdvar);
+}
+
+Symsptr MbD::FunctionX::differentiateWRTx()
+{
+	assert(false);
+	return Symsptr();
+}