│123 │213 │——— │132 │312 │——— │231 │321 │——— _Four_ will make four times as many changes as _three_. For there are four times three figures to be had out of four, and not twice three the same figures, which are to be produced by casting away each of the four figures by turns. First cast away 4, and 123 will remain; cast away 3, and 124 will remain; cast away 2, and 134 will remain; and lastly, casting away 1, and 234 will remain; so that here is 123, 124, 134, 234, and not twice three the same figures. Now each three may be varied six ways, according to the preceding Example. Then to the six changes which each three makes, add the fourth figure which is wanting; as to the six changes on 123 add the 4, to the six changes on 124 add the 3, to the six changes on 134 add the 2, and to the six changes on 234 add the 1, which renders the changes compleat; for then the four figures stand twenty four times together, and not twice alike, as here appears. │1234 │2134 │———— │1324 │3124 │———— │2314 │3214 │———— │1243 │2143 │———— │1423 │4123 │———— │2413 │4213 │———— │1342 │3142 │———— │1432 │4132 │———— │3412 │4312 │———— │2341 │3241 │———— │2431 │4231 │———— │3421 │4321