1 1.1 christos Here is a comparison matrix which shows a case in which 2 1.1 christos it is possible for the forward and backward scan in `diag' 3 1.1 christos to meet along a nonzero length of diagonal simultaneous 4 1.1 christos (so that bdiag[d] and fdiag[d] are not equal) 5 1.1 christos even though there is no snake on that diagonal at the meeting point. 6 1.1 christos 7 1.1 christos 8 1.1 christos 85 1 1 1 159 1 1 17 9 1.1 christos 1 2 3 4 10 1.1 christos 60 11 1.1 christos 1 2 12 1.1 christos 1 13 1.1 christos 2 2 3 4 14 1.1 christos 71 15 1.1 christos 3 3 4 5 16 1.1 christos 85 17 1.1 christos 4 3 4 5 18 1.1 christos 17 19 1.1 christos 5 4 5 20 1.1 christos 1 21 1.1 christos 6 4 5 6 22 1.1 christos 183 23 1.1 christos 7 5 6 7 24 1.1 christos 10 25 1.1 christos 8 6 7 26 1.1 christos 1 27 1.1 christos 9 6 7 8 28 1.1 christos 12 29 1.1 christos 7 8 9 10 30 1.1 christos 13 31 1.1 christos 10 8 9 10 32 1.1 christos 14 33 1.1 christos 10 9 10 34 1.1 christos 17 35 1.1 christos 10 10 36 1.1 christos 1 37 1.1 christos 10 9 10 38 1.1 christos 1 39 1.1 christos 8 10 10 10 40 1.1 christos 183 41 1.1 christos 8 7 9 9 9 42 1.1 christos 10 43 1.1 christos 7 6 8 9 8 8 44 1.1 christos 1 45 1.1 christos 6 5 7 7 46 1.1 christos 1 47 1.1 christos 5 6 6 48 1.1 christos 1 49 1.1 christos 5 5 5 50 1.1 christos 50 51 1.1 christos 5 4 4 4 52 1.1 christos 1 53 1.1 christos 4 3 3 54 1.1 christos 85 55 1.1 christos 5 4 3 2 2 56 1.1 christos 1 57 1.1 christos 2 1 58 1.1 christos 17 59 1.1 christos 5 4 3 2 1 1 60 1.1 christos 1 61 1.1 christos 1 0 62 1.1 christos 85 1 1 1 159 1 1 17 63 1.1 christos 64 1.1 christos 65 1.1 christos 66 1.1 christos 67 1.1 christos 68 1.1 christos 69 1.1 christos 70 1.1 christos 71 1.1 christos 72