The string that is obtained by concatenating the elements of the first component(s) of the ordered pairs (composite variable(s)) is 
and represents the input string to the LBA M. Concatenating the second component we get the string 
which is the initial configuration of the LBA M on the input string .
and represents the input string to the LBA M. Concatenating the second component we get the string which is the initial configuration of the LBA M on the input string .
Rules 3 and 4 given below are used to simulate the computations of the LBA M.
- For every move
of the LBA include
in P
and 
- Similarly for every move
of the LBA include
in P. 
whenever
is a move of the LBA.