… So, in this case [1,“c”] and [1,“b”] are equivalent, and

their order

is un-important …

From http://en.wikipedia.org/wiki/Stable_sort :

Stability: stable sorting algorithms maintain the relative order

of records with equal keys (i.e. values). That is, a sorting algorithm

is stable if whenever there are two records R and S with the same

key and with R appearing before S in the original list, R will appear

before S in the sorted list.

cheers

Simon