1. A computer assisted method for creating a semantic knowledge base for a document corpus describing physical or tangible objects, consisting of unique sentential propositions, such that a single sentential proposition represents the entire meaning of a simple or complex sentence, said method comprising the steps of: (a) segmenting at least a portion of a document corpus into individual sentences using a computer processor; and (b) reducing each said sentence to one or more simple or complex sentences; and (c) displaying candidate propositions to a domain expert for each said simple or complex sentence using a computer processor; and (d) said domain expert creating a unique sentential proposition to represent the entire meaning for each said simple or complex sentence whose meaning is not represented in said knowledge base using a knowledge editor; and (e) adding said sentential proposition(s) using a computer processor to said knowledge base.