Add, delete, or replace one component in the current model.
XSPEC> editmod [<delimeter>] <component1> <delimeter> <component2> <delimeter> ... <componentN> [<delimeter>]
where <delimeter> is some combination of (, +, *, and ), and <componentJ> is one of the models known to XSPEC. The arguments for this command should specify a new model, with the same syntax as the previous model, except for one component which may be either added, deleted, or changed to a different component type. XSPEC then compares the entered model with the current model, determines which component is to be modified (prompting the user if necessary to resolve ambiguities) and then modifies the model, prompting the user for any new parameter values which may be needed.