// randomized dining philosophers [LR81] // dxp/gxn 12/12/99 // atomic formulae // left fork free and right fork free resp. formula lfree = (p2>=0&p2<=4)|p2=6|p2=10; formula rfree = (p3>=0&p3<=3)|p3=5|p3=7|p3=11; module phil1 p1: [0..11]; [] p1=0 -> (p1'=0); // stay thinking [] p1=0 -> (p1'=1); // trying [] p1=1 -> 0.5 : (p1'=2) + 0.5 : (p1'=3); // draw randomly [] p1=2 & lfree -> (p1'=4); // pick up left [] p1=2 & !lfree -> (p1'=2); // left not free [] p1=3 & rfree -> (p1'=5); // pick up right [] p1=3 & !rfree -> (p1'=3); // right not free [] p1=4 & rfree -> (p1'=8); // pick up right (got left) [] p1=4 & !rfree -> (p1'=6); // right not free (got left) [] p1=5 & lfree -> (p1'=8); // pick up left (got right) [] p1=5 & !lfree -> (p1'=7); // left not free (got right) [] p1=6 -> (p1'=1); // put down left [] p1=7 -> (p1'=1); // put down right [] p1=8 -> (p1'=9); // move to eating (got forks) [] p1=9 -> (p1'=10); // finished eating and put down left [] p1=9 -> (p1'=11); // finished eating and put down right [] p1=10 -> (p1'=0); // put down right and return to think [] p1=11 -> (p1'=0); // put down left and return to think endmodule // construct further modules through renaming module phil2 = phil1 [ p1=p2, p2=p3, p3=p1 ] endmodule module phil3 = phil1 [ p1=p3, p2=p1, p3=p2 ] endmodule // labels label "hungry" = ((p1>0)&(p1<8))|((p2>0)&(p2<8))|((p3>0)&(p3<8)); label "eat" = ((p1>=8)&(p1<=9))|((p2>=8)&(p2<=9))|((p3>=8)&(p3<=9));