For a given test set that provides 100% t-way coverage for n variables, (t+k)-way combination coverage is the proportion of (t+k)-way combinations of n variables for which all variable-values configurations are fully covered.
For a given test set that provides 100% t-way coverage for n variables, (t+k)-way combination coverage is the proportion of (t+k)-way combinations of n variables for which all variable-values configurations are fully covered.