A logic question in `duplicate_tracer`

[wegank]

In the following file:

msolve/src/msolve/duplicate.c

Lines 61 to 71 in ff6fb15

	/* position of non redundant elements in Gbasis */
	btrace[i]->lmps = (bl_t *)calloc((unsigned long)btrace[0]->lml,
	sizeof(bl_t));
	memcpy(btrace[i]->lmps, btrace[0]->lmps,
	(unsigned long)btrace[0]->lml * sizeof(bl_t));
	/* non-redundant lead mon. as short divmask */
	btrace[i]->lm = (sdm_t *)calloc((unsigned long)btrace[0]->lml,
	sizeof(sdm_t));
	memcpy(btrace[0]->lm, btrace[i]->lm,
	(unsigned long)btrace[0]->lml * sizeof(sdm_t));

why is the second memcpy in the opposite direction?