1. In a process where the condition of a plurality of logic elements, including a first logic element and a last logic element, controls an action, a method for preparing a computer program for determining said action, said program being for execution in a digital computer having a processor and a memory, said method comprising the steps of: developing an expression for storage in said memory, said expression defining the effect said logic elements have on said action; for each condition for each logic element, using said processor for examining said expression to determine another logic element within said expression which controls said action, thereby defining condition determining control paths; generating code for execution by said computer for examining the conditions of only those logic elements necessary to determine the action in an order directed by said condition determining control paths.