MODULO
The variable MODULO contains a real prime number for use with the modular operations. The default value is 13. It is used by ADDTMOD, DIV2MOD, DIVMOD, EXPANDMOD, FACTORMOD, GCDMOD, INVMOD, MODSTO, MULTMOD, POWMOD, RREFMOD, and SUBTMOD.
PERIOD
Contains the period for CAS periodic operations. The default value is 2π.
PRIMIT
Contains a primitive (subexpression) used temporarily for
REALASSUME
The variable REALASSUME contains a list of variables which the CAS assumes are real values.
VX
The variable VX contains the name of the default variable to use for CAS commands which operate on a default variable. It is used by DERVX, INTVX, SIGMAVX, and SOLVEVX.