ATM
Version of Hopcroft & Ullman's TM for {0^n 1^n : n > 0} with 2-way infinite tape
0 1	// input alphabet, note such comments are permitted at the end of the line
0 1 X Y B // tape alphabet
1	// number of tapes
1	// number of tracks on tape 0
2	// tape 0 is 2-way infinite
q0	// the initial state
q4      // final state(s)
q0  0  q1  X  R  // the transitions do not use "+" since there is only one track
q0  Y  q3  Y  R
q1  0  q1  0  R
q1  1  q2  Y  L
q1  Y  q1  Y  R
q2  0  q2  0  L
q2  X  q0  X  R
q2  Y  q2  Y  L
q3  Y  q3  Y  R
q3  B  q4  B  R
end 	//required