Function: facsum (<expr>, <arg_1>, ..., <arg_n>) Returns a form of <expr> which depends on the arguments <arg_1>, ..., <arg_n>. The arguments can be any form suitable for
ratvars, or they can be lists of such forms. If the arguments are not lists, then the form returned is fully expanded with respect to the arguments, and the coefficients of the arguments are factored. These coefficients are free of the arguments, except perhaps in a non-rational sense.
If any of the arguments are lists, then all such lists are combined into a single list, and instead of calling
factor on the coefficients of the arguments,
facsum calls itself on these coefficients, using this newly constructed single list as the new argument list for this recursive call. This process can be repeated to arbitrary depth by nesting the desired elements in lists.
It is possible that one may wish to
facsum with respect to more complicated subexpressions, such as
log (x + y). Such arguments are also permissible.
Occasionally the user may wish to obtain any of the above forms for expressions which are specified only by their leading operators. For example, one may wish to
facsum with respect to all
logs. In this situation, one may include among the arguments either the specific
logs which are to be treated in this way, or alternatively, either the expression
operator (log) or
operator (log). If one wished to
facsum the expression <expr> with respect to the operators <op_1>, ..., <op_n>, one would evaluate
facsum (<expr>, operator (<op_1>, ..., <op_n>)). The
operator form may also appear inside list arguments.
In addition, the setting of the switches
nextlayerfactor may affect the result of
There are also some inexact matches for
?? facsum to see them.
(%o1) true (%i2)