Formally, a LBA is a nondeterministic TM M = (Q,,,, q₀, B, <, >, F) satisfying the following conditions:

1. The input alphabet, must contain two special symbols < and >, the left and right end markers, respectively which do not appear in any input string.
2. (q, <) can contain only element of the form ( p, <, R ) and (q, >) can contain only elements of the form (p, >, L) for any q, p Q .

[ Note: All other elements are identical to the corresponding elements of a TM ]