// mutual exclusion [PZ82]
// dxp/gxn 19/12/99

mdp

// atomic formula
// none in low, high, tie
formula none_lht = p2!=4..13 & p3!=4..13;
// some in admit
formula some_a	 = p2=14..15 | p3=14..15;
// some in high, admit
formula some_ha	 = p2=4..5,10..15 | p3=4..5,10..15;
// none in high, tie, admit
formula none_hta = p2=0..3,7..8 & p3=0..3,7..8;
// none in enter
formula none_e	 = p2!=2..3 & p3!=2..3;

// process 1
module process1

	p1: [0..15];
	
	[] p1=0 -> (p1'=0);
	[] p1=0 -> (p1'=1);
	[] p1=1 -> (p1'=2);
	[] p1=2 &  (none_lht | some_a) -> (p1'=3);
	[] p1=2 & !(none_lht | some_a) -> (p1'=2);
	[] p1=3 -> (p1'=4);
	[] p1=3 -> (p1'=7);
	[] p1=4 &  some_ha -> (p1'=5);
	[] p1=4 & !some_ha -> (p1'=10);
	[] p1=5 -> (p1'=6);
	[] p1=6 &  some_ha -> (p1'=6);
	[] p1=6 & !some_ha -> (p1'=9);
	[] p1=7 &  none_hta -> (p1'=8);
	[] p1=7 & !none_hta -> (p1'=7);
	[] p1=8  -> (p1'=9);
	[] p1=9  -> 0.5 : (p1'=4) + 0.5 : (p1'=7);
	[] p1=10 -> (p1'=11);
	[] p1=11 &  none_lht -> (p1'=13);
	[] p1=11 & !none_lht -> (p1'=12);
	[] p1=12 -> (p1'=0);
	[] p1=13 -> (p1'=14);
	[] p1=14 &  none_e -> (p1'=15);
	[] p1=14 & !none_e -> (p1'=14);
	[] p1=15 -> (p1'=0);
	
endmodule

// construct further modules through renaming
module process2 = process1 [p1=p2, p2=p1] endmodule
module process3 = process1 [p1=p3, p3=p1] endmodule