_data_beg
v = _data_beg(t, (int) SizeNext(c, t));
_adjust_cursor(f, _data_beg(Buf(c), BufSize(c)));
_adjust_cursor(f, _data_beg(LineBuf(c, Y(f)), Xmax(f)));
v = _data_beg(vbeg + Xmax(f) - siz, siz);
v = _data_beg(v, (int)(t - v));
char * v = _data_beg(Buf(f), BufSize(f));
char * v = _data_beg(Buf(f), BufSize(f));
extern char * _data_beg(char *, int);