Set the previous candidate as the current candidate
#include <canna/RK.h> int RkPrev(cxnum) int cxnum;
RkPrev sets the previous candidate as the current candidate or, if the current candidate is the first candidate, moves to the last candidate.
If successful, this function moves the current candidate in the context and returns the current candidate number after the move. It returns 0, without doing anything, if it has been run in a nonconversion mode context.