







s_{i} \models f and s_{i} \models g 

s_{i} \models "\bigcirc f 


for all s_{j} such that (s_{i},t,s_{j}) Î d . s_{j} \models f 

s_{i} \models $\bigcirc f 


there exists s_{j} such that (s_{i},t,s_{j}) Î d . s_{j} \models f 



for all allowed sequences (s_{i},s_{i+1},¼), 



$j [ j ³ i Ùs_{j} \models g Ù "k [i £ k < j Þ s_{k} \models f]] 



for some allowed sequence (s_{i},s_{i+1},¼), 



$j [ j ³ i Ùs_{j} \models g Ù "k [i £ k < j Þ s_{k} \models f]] 
