+ (when (and colinc (<= colinc 0))
+ (error 'format-error
+ :complaint "The value of colinc is ~a, should be a positive integer"
+ :args (list colinc)))
+ (when (and mincol (< mincol 0))
+ (error 'format-error
+ :complaint "The value of mincol is ~a, should be a non-negative integer"
+ :args (list mincol)))