seqfn
*seq = seqfn(p->seq, 0);
*ps = seqfn(p->seq, 0);
*seq = seqfn(p->seq, 0);
*seq = seqfn(p->seq++, 0);
*seq = seqfn(p->seq-1, 1);
short seqfn(unsigned short seq, unsigned short fn);
*seqp = seqfn(p->seq, p->frag);
*seq = seqfn(p->seq++, 0);
*pseq = seqfn(p->seq, p->frag++);
*seq = seqfn(p->seq, p->frag++);