+void neg(struct Thread* thread, Argument argument) {
+ assert(!Stack_isEmpty(&(thread->stack)));
+ Object result = Stack_pop(&(thread->stack));
+ assert(result.type == INTEGER);
+
+ result.value.integer = -(result.value.integer);
+
+ Stack_push(&(thread->stack), result);
+}
+
+void pop(struct Thread* thread, Argument argument) {