A Mechanized Proof Procedure for Free Intensional Logics

Included amongst the i n t e n s i o n a l l o g i c s are those dea l i ng w i t h o b l i g a t i o n (deont ic l og i c ) , necess i ty (modal l o g i c ) , t ime (tense l o g i c ) , and var ious o ther i n t e n s i o n a l concepts. These l o g i c s were developed to fo rma l i ze the semantics o f n a t u r a l language d iscourses . The i n t e n s i o n a l l o g i c s s tud ied here are extensions of some of the senteni a l l o g i c s known as the normal i n t e n s i o n a l l o g i c s . These l o g i c s inc lude the modal l o g i c s K, M, B, S4, and S5 and t h e i r deont ic and tense l o g i c coun te rpar ts . The c losure o f the a c c e s s i b i l i t y r e l a t i o n in these l o g i c s can be r e a d i l y computed, a convenient p roper ty f o r mechanizing p r o o f s .