PLACE a1, a2, a3, a4, a5, xt, xf, yt, yf, b1, b2, b3, b4, b5, b6, b7, b8; MARKING a1: 1, b1: 1, xf: 1, yf: 1; TRANSITION s1 CONSUME a1: 1; PRODUCE a2: 1; TRANSITION s2 CONSUME a2: 1, xf: 1; PRODUCE a3: 1, xt: 1; TRANSITION s3 CONSUME a2: 1, xt: 1; PRODUCE a3: 1, xt: 1; TRANSITION s4 CONSUME a3: 1, yf: 1; PRODUCE a4: 1, yf: 1; TRANSITION s5 CONSUME a3: 1, yt: 1; PRODUCE a3: 1, yt: 1; TRANSITION s6 CONSUME a4: 1; PRODUCE a5: 1; TRANSITION s7 CONSUME a5: 1, xf: 1; PRODUCE a1: 1, xf: 1; TRANSITION s8 CONSUME a5: 1, xt: 1; PRODUCE a1: 1, xf: 1; TRANSITION t1 CONSUME b1: 1; PRODUCE b2: 1; TRANSITION t2 CONSUME b2: 1, yt: 1; PRODUCE b3: 1, yt: 1; TRANSITION t3 CONSUME b2: 1, yf: 1; PRODUCE b3: 1, yt: 1; TRANSITION t4 CONSUME b3: 1, xt: 1; PRODUCE b4: 1, xt: 1; TRANSITION t5 CONSUME b3: 1, xf: 1; PRODUCE b7: 1, xf: 1; TRANSITION t6 CONSUME b4: 1, yf: 1; PRODUCE b5: 1, yf: 1; TRANSITION t7 CONSUME b4: 1, yt: 1; PRODUCE b5: 1, yf: 1; TRANSITION t8 CONSUME b5: 1, xf: 1; PRODUCE b6: 1, xf: 1; TRANSITION t9 CONSUME b5: 1, xt: 1; PRODUCE b5: 1, xt: 1; TRANSITION t10 CONSUME b6: 1; PRODUCE b2: 1; TRANSITION t11 CONSUME b7: 1; PRODUCE b8: 1; TRANSITION t12 CONSUME b8: 1, yf: 1; PRODUCE b1: 1, yf: 1; TRANSITION t13 CONSUME b8: 1, yt: 1; PRODUCE b1: 1, yf: 1;