<< [(key word)] system_variable result >> or << [(key word) value] system_variable result >> << [(key word) optional arg] system_variable result >> The primitive returns the value of a given system constant. The primitive sets the value of a given system constant. PrintDollar [0,1,2], Wrap, P, N, NN, M, MM, L, LL, C, CC,ringName, CurrentRingp, Verbose, UseCriterion1, UseCriterion2B, ReduceLowerTerms, CheckHomogenization, Homogenize, Sugar, Homogenize_vec, Statistics, StackPointer, StandardOperandStack, ErrorStack, ErrorMessageMode, WarningMessageMode, CatchCtrlC, Strict, CurrentContextp, NullContextp, Strict2, QuoteMode SigIgn, KSPushEnvMode, PrimitiveContextp, KanGBmessage, orderMatrix, gbListTower, Schreyer, outputOrder, multSymbol, variableNames, Version, AvoidTheSameRing, RingStack, LeftBracket, RightBracket, AutoReduce, Ecart, EcartAutomaticHomogenization DoCancel, DebugContentReduction RestrictedMode (cf. or_attr 8), SecureMode(obsolete) UseDsmall, COutput Example: [(N)] system_variable (maximum number of variables)/2. [(x) (var) 3] system_variable The 3rd variable. [(D) (var) 4] system_variable The 4th differential operator. [(PrintDollar) 0] system_variable Set the global variable PrintDollar to 0 DebugReductionEcart (bit): (2) * (1) find_reducer,in(r) (any) cont (4) #+[rat division, + ecartd] (8) check the order. DoCancel (bit): (2) always_reduce_content (1) Noro_strategy (4) DoCancel_in_reduction1