Indicating Equality Constraints: ax=b
0 <= b - ax <= 0 i=1 j=0 k=0
eps <= b - ax <= U i=0 j=1 k=0
L <= b - ax <= -eps i=0 j=0 k=1
L*(1-i) <= b – ax <= U*(1-i) (i)
L – (L- eps)*(j) <= b-ax <= U – (U + eps)*(k) (ii)
L*1 <= b – ax <= U*1, L – (L- eps)<= b-ax <= U – 0
L*1 <= b – ax <= U*1, L - 0 <= b-ax <= U – (U + eps)