1. A computing device of reduction type for reducing programs stored therein, comprising: at least one port means for connecting said computing device with at least one external device connected to said at least one port means; an active associative storage means for associatively storing and retrieving data elements, said active associative storage means being connected to said at least one port means and comprising a plurality of storage cell means for storing and executing at least part of a computer program stored therein; a structural arithmetic means comprising a matrix of interconnected registers of storage cell means for storing and reducing at least part of computer programs stored therein; and a bus means for connecting each of said storage cell means of said active associative storage means to said structural arithmetic means and to said at least one port means, said at least one port means comprising comparison means for comparing, by a unification operation, data provided by said at least one external device to said at least one port means with data stored in at least one of a plurality of storage cells contained in said port means, said data provided by said at least one external device and said stored data each having possible undefined data elements or partially defined elements.