--- /dev/null
+#ifndef INVERTERSCHEMA_H
+#define INVERTERSCHEMA_H
+
+
+#include "blockSchema.h"
+
+/**
+ * An inverter : a special symbol corresponding to '*(-1)'
+ * to create more compact diagrams
+ */
+class inverterSchema : public blockSchema
+{
+
+ public:
+ friend schema* makeInverterSchema (const string& color);
+
+ virtual void draw(device& dev);
+ private:
+ inverterSchema (const string& color);
+
+};
+
+#endif // INVERTERSCHEMA_H