1. An computer apparatus capable of assisting a user in decision-making in respect of a selected domain, comprising: (a) one or more input interfaces capable of receiving input data representing current information about conditions in a domain; (b) one or more memories for storing a plurality of items of data about said domain and also items of data from a database representing information about the domain and information external to the domain; (c) a decision processor capable of generating output data representing a choice, in accordance with its programmed algorithms, axioms and rules, based on data from said memory and from said input interface(s); (d) a storage device for storing an operator system algorithm and data; (e) a computer programmed to compute said operator system algorithm; (f) one or more user interfaces that enable a user to interact with said decision processor; wherein said user interface may comprise a said input interface; (g) a connection bus capable of effecting connections among the input interface; the memorie(s), the decision processor(s) and user interface(s); wherein said user interface permits a user to select selectable data and a selectable operator system algorithm, one or more selectable domains, selectable axioms and selectable rules; and wherein said decision processor is capable of generating output data based on said selections made.