Ambiguity in Limited Entry Decision Tables
The use of decision tables as a tool in systems
analysis and for program specification is now 
becoming accepted.  Rules on redundancy, contradiction,
and completeness for limited entry tables were 
published in 1963.  These are usually used for checking,
preceded if necessary by a conversion from extended 
to limited entry form.  Processors which automatically
translate tables to more conventional program 
usually base their diagnostic facilities on these rules.
 In this paper it is suggested that these rules 
are unsatisfactory and that the important aspect of
checking is to eliminate ambiguity from tables.  
Ambiguity is defined and discussed, and a procedure for
producing checked-out decision tables is proposed. 
 The theoretical basis of the algorithm used is established.
The importance of well-designed diagnostic 
facilities in decision table processors is emphasized.
CACM October, 1968
King, P. J. H.
