public TYPE_1 diff ( TYPE_1 expr ) { return TYPE_2 . METHOD_1 ( TYPE_3 . METHOD_1 ( expr ) ) . METHOD_2 ( arg . diff ( expr ) ) ; } 

public TYPE_1 diff ( TYPE_1 expr ) { return TYPE_2 . METHOD_1 ( TYPE_3 . METHOD_1 ( arg ) ) . METHOD_2 ( arg . diff ( expr ) ) ; } 
