PolynomialGCD[poly_1, poly_2, ...] gives the greatest common divisor of the polynomials poly_i. PolynomialGCD[poly_1, poly_2, ..., Modulus -> p] evaluates the GCD modulo the ...
PrincipalValue is an option for Integrate that specifies whether the Cauchy principal value should be found for a definite integral.
RenameDirectory["dir_1", "dir_2"] renames the directory dir_1 to dir_2.
SaveDefinitions is an option to Manipulate and related functions that specifies whether current definitions relevant for the evaluation of the expression being manipulated ...
ScheduledTaskObject[id, expr, spec, ...] is a task object specifying future evaluation of expr according to spec.
ScriptSizeMultipliers is an option for Style that specifies how much smaller to render each successive level of subscripts, etc.
SetSystemOptions["name" -> value] resets the value for the internal system option with the specified name.
StackComplete[expr] evaluates expr with intermediate expressions in evaluation chains included on the stack.
StringFormat["string"] attempts to determine what ImportString format could be used to import the string " string".
StringTrim["string"] trims whitespace from the beginning and end of " string".StringTrim["string", patt] trims substrings matching patt from the beginning and end.