There was a logical error in my last commit that Ahmed Ghazy found and fixed; my example I was working with had only two sets of symmetries and the problem happened not to show up. I just pushed the fix to the opencircuitdesign.com repo.

Can't

E1

/

E2

also become NULL during the inner loops ? (

while (E1->graph != Circuit1->file) E1 = E1->next;

)

@tnt: It has already been established that C1 = C2, that there are the same number of entries for circuit 1 and circuit 2 in the list. So for every valid circuit 1 entry there must be a valid corresponding circuit 2 entry. Whichever pair is the last one, one of the two entries is the last entry in the linked list, and moving to ->next will become null, and the loop will exit. This should never happen in the inner loop.

Tx for the explanation. The fix is similar to what I had already applied (except I was also checking the inner loops which is useless).