Towards Light-Weight Probabilistic Model Checking

Table 2

Sample properties for a single robot.

Property	Informal, Natural language and Prism specifications	Result
1	The robot eventually grabs food with a probability greater than 0.9	TRUE
	s  =  3 will eventually hold, until then true holds with a probability >0.9
	P  >  0.9  [true  U  s  =  3]
2	What is the probability that the robot grabs food within 50 s?	0.55
	s  =  3 will eventually hold within time bound [0, 50], until then true holds with a probability?
	P  =  ?  [true  U[0,  50]  s  =  3]
3	What is the probability that the robot searches for food for 50 s. before going to home?	0.39
	s  =  1 will hold within time bound [0, 50], until then 𝑠=0 holds with a probability?
	P  =  ?  [s  =  0  U[0,  50]  s  =  1]
4	The robot never goes to home within 50 s	FALSE
	s!  =  1 always holds within time bound [0,50] with a probability >=1
	P  >=  1  [G[0,  50]  s!  =  1]
5	The robot does not continuously search for food forever	TRUE
	s  =  0 always holds with a probability <=0
	P  <=  0  [G  s  =  0]
6	When searching starts, the robot eventually grabs food with a probability greater than 0.6	TRUE
	s  =  0 is always followed by s  =  3 with a probability >0.6
	P  >  0.6  [G  (s  =  0  =>  P  >=  1  [true  U  s  =  3])]
7	The robot repeats its behaviour forever (e.g. searches for food)	TRUE
	s  =  0 holds infinitely often with a probability >=1
	P  >=  1  [G  (P  >=  1  [true  U  s  =  0])]